// networking

What Is an IP Address?

An IP address is a numerical address used to identify and communicate with devices and services across an IP network, including the internet.

// definition

IP stands for Internet Protocol

An IP address is an address assigned to a network interface using the Internet Protocol. It allows data to be addressed and routed between devices across networks.

// basic idea

Think of it as a network address

When data travels across a network, computers need to know where it should be sent.

Your device | v Network | v IP address | v Destination device or server

The Internet Protocol uses IP addresses as part of this addressing and routing process.

// IPv4

What does an IPv4 address look like?

One common type of IP address is an IPv4 address.

It is written as four decimal numbers separated by dots.

192.168.1.25

Each section represents 8 bits and can range from 0 to 255.

192 . 168 . 1 . 25 | | | | 8 bits 8 bits 8 bits 8 bits

IPv4 addresses are therefore 32 bits long.

4 x 8 bits = 32 bits

// address space

How many IPv4 addresses are possible?

A 32-bit address provides:

2^32 = 4,294,967,296

That is approximately 4.3 billion possible IPv4 addresses.

Not all of those addresses are available as ordinary public internet addresses because portions of the address space are reserved for particular purposes.

// IPv6

What is IPv6?

The newer version of Internet Protocol addressing is IPv6.

IPv6 addresses are 128 bits long and are normally written in hexadecimal.

2001:0db8:85a3:0000:0000:8a2e:0370:7334

IPv6 provides a vastly larger address space than IPv4.

IPv4 = 32 bits IPv6 = 128 bits

// comparison

IPv4 vs IPv6

IPv4

32-bit addresses written using four decimal numbers separated by dots.

IPv6

128-bit addresses normally written using hexadecimal groups separated by colons.

// public IP

What is a public IP address?

A public IP address is an address used for communication across the public internet.

For example, a home router may have a public IP address assigned by an internet service provider.

Internet | v Public IP address | v Router | v Local network

Public IP addresses must be globally routable and cannot simply be duplicated arbitrarily across the public internet.

// private IP

What is a private IP address?

Devices inside homes and businesses commonly use private IP addresses.

Common IPv4 private address ranges include:

10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255

These addresses can be reused on different private networks because they are not routed directly across the public internet.

// NAT

How can many devices share one public IP address?

Home and business networks commonly use Network Address Translation, or NAT.

Laptop 192.168.1.10 Phone 192.168.1.11 TV 192.168.1.12 | v Router | v One public IP address | v Internet

NAT allows multiple devices using private addresses to communicate through a smaller number of public IP addresses.

// assignment

Static vs dynamic IP addresses

Static IP

An address intended to remain fixed unless it is deliberately changed.

Dynamic IP

An address that may be assigned automatically and can change over time.

Internet service providers often assign dynamic public IP addresses to residential customers, while servers and business services may use static addressing where a stable address is useful.

// DHCP

How do devices get an IP address?

On many local networks, IP addresses are assigned automatically using:

DHCP Dynamic Host Configuration Protocol

A DHCP server can provide devices with information such as an IP address, subnet configuration, default gateway and DNS servers.

// DNS

IP addresses and domain names

Humans generally prefer names such as:

example.com

Computers communicating over IP networks ultimately use network addresses.

DNS helps connect these ideas.

Domain name | v DNS | v IP address | v Server

For example, an A record can map a hostname to an IPv4 address, while an AAAA record can map a hostname to an IPv6 address.

// URL

An IP address is not a URL

Consider:

https://example.com/products/item

This is a URL.

The hostname:

example.com

can be resolved through DNS to an IP address.

The rest of the URL identifies the protocol and the resource being requested.

// routing

How IP addresses help route data

Data sent using Internet Protocol is divided into packets.

IP packets contain addressing information including source and destination IP addresses.

Source IP | v Packet | v Routers | v Destination IP

Routers examine network information and decide where packets should be forwarded next.

// subnet

What is a subnet?

IP networks can be divided into smaller networks called subnets.

You may see notation such as:

192.168.1.0/24

The /24 is CIDR notation. It indicates that the first 24 bits describe the network portion of the IPv4 address.

192.168.1.0/24 Network portion = first 24 bits Host portion = remaining 8 bits

// special addresses

What is 127.0.0.1?

The IPv4 address:

127.0.0.1

is a loopback address commonly associated with:

localhost

It refers back to the local computer rather than another device on the internet.

Developers often use localhost when testing applications on their own machine.

// web servers

Does every website have its own IP address?

Not necessarily.

Multiple websites can share the same server and the same public IP address.

Website A Website B Website C | v Shared web server | v 203.0.113.10

Modern web servers can determine which website is being requested from information such as the hostname supplied by the browser.

// location

Can an IP address reveal your exact location?

An IP address can sometimes provide approximate geographic information, such as a country, region or general area.

However, an IP address does not inherently contain a person's exact home address or precise physical location.

Important: IP geolocation databases are estimates. Their results can be inaccurate, and networks such as mobile networks, VPNs and corporate systems can make the apparent location very different from the user's actual location.

// changing addresses

Can your IP address change?

Yes.

A device may receive a different IP address when:

Network changes

Connecting to a different Wi-Fi or mobile network can give the device different addressing.

DHCP changes

A dynamically assigned address can change when its network lease changes.

ISP changes

An internet provider may assign a different public address over time.

VPN usage

Internet services may see the VPN server's public IP address rather than the user's ordinary public IP.

// mental model

The easiest way to remember it

Domain name = human-readable name DNS = translates names into network information IP address = network address Router = forwards packets between networks Server = provides a service URL = identifies a specific web resource

The IP address is therefore one of the fundamental pieces of information used to move data from one network location to another.

// summary

An IP address identifies a network destination.

An IP address is an address used by the Internet Protocol to identify network interfaces and route data. IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses. Devices may use public or private addresses, and DNS helps connect human-readable domain names to IP addresses.

// DNS

What Is a Nameserver?

A nameserver is part of the Domain Name System. It helps computers discover the DNS records associated with a domain name.

// definition

A nameserver is a DNS server

A nameserver is a server that responds to DNS queries. When talking about domains, the term usually means an authoritative nameserver: a server responsible for providing the official DNS records for a particular DNS zone.

// basic idea

What does a nameserver actually do?

Imagine someone enters:

www.example.com

A computer needs to find out where that hostname should lead.

DNS eventually reaches the nameservers responsible for example.com and asks them for the relevant DNS information.

Domain name | v DNS lookup | v Authoritative nameserver | v DNS record | v Destination

// example

What does a nameserver look like?

A domain may use nameservers such as:

ns1.example-dns.com ns2.example-dns.com

These are hostnames identifying DNS servers.

It is common for a domain to use more than one nameserver so DNS can continue working if one server becomes unavailable.

// records

Nameservers provide DNS records

The nameserver does not normally contain the website itself. Instead, it provides information describing how the domain should behave.

A

Maps a hostname to an IPv4 address.

AAAA

Maps a hostname to an IPv6 address.

CNAME

Makes one hostname an alias of another hostname.

MX

Identifies the mail servers used to receive email.

TXT

Stores text used for verification, security policies and other purposes.

NS

Identifies the nameservers responsible for a DNS zone.

// authoritative

What is an authoritative nameserver?

An authoritative nameserver is considered an official source of DNS information for the DNS zones it serves.

example.com | v Authoritative nameserver | +-- A record +-- CNAME record +-- MX record +-- TXT record

If another DNS server asks for information about example.com, the authoritative nameserver can provide the records configured for that zone.

// NS records

How does DNS know which nameservers to use?

DNS uses NS records.

NS stands for:

Name Server

A simplified configuration might look like:

example.com NS ns1.example-dns.com NS ns2.example-dns.com

These records identify the nameservers responsible for that DNS zone.

// hierarchy

Nameservers are part of the DNS hierarchy

DNS is organised as a hierarchy rather than one enormous central database.

For example:

DNS root | v .com | v example.com | v www.example.com

Each level can help direct DNS queries towards the servers responsible for the next level.

// delegation

What is DNS delegation?

Delegation means assigning responsibility for a DNS zone to particular authoritative nameservers.

For example, the DNS infrastructure responsible for the .com top-level domain can indicate which nameservers are responsible for example.com.

.com | v "Ask these nameservers about example.com" | v ns1.example-dns.com ns2.example-dns.com

// registrar

Where do you set nameservers?

For a registered domain, nameserver settings are commonly managed through the company acting as the domain registrar.

Domain registrar | v Nameserver settings | v DNS provider | v DNS records

You might therefore register your domain with one company while using another company to provide its DNS.

// distinction

Domain registrar, nameserver and web host are different

Domain registrar

Manages the registration of your domain name.

Nameserver

Answers DNS queries and provides DNS records for zones it is authoritative for.

DNS provider

Operates the DNS infrastructure where you manage your records.

Web host

Runs or stores the website or application reached through the domain.

// changing nameservers

What happens when you change nameservers?

Changing a domain's nameservers changes which DNS servers are authoritative for that domain.

Before: Domain | v Old nameservers | v Old DNS records After: Domain | v New nameservers | v New DNS records

Important: changing nameservers is different from changing an individual DNS record. A nameserver change can move responsibility for the entire DNS zone to another provider.

// records vs nameservers

Changing a DNS record vs changing nameservers

Change a DNS record

Keep the existing DNS provider but modify something such as an A, CNAME, MX or TXT record.

Change nameservers

Change the DNS servers responsible for providing the authoritative records for the domain.

// resolver

Nameserver vs DNS resolver

Another important distinction is between a recursive resolver and an authoritative nameserver.

Recursive resolver

Searches for DNS information on behalf of the user and may cache the result.

Authoritative nameserver

Supplies the authoritative DNS records for the zones for which it is responsible.

Browser | v Recursive DNS resolver | v Authoritative nameserver | v DNS answer

// redundancy

Why do domains normally have multiple nameservers?

Domains usually have at least two authoritative nameservers.

ns1.example-dns.com ns2.example-dns.com

This improves resilience. If one nameserver cannot answer a query, another may still be available.

// caching

Why can nameserver changes take time?

DNS information is cached.

After changing nameservers, some DNS resolvers may still temporarily remember older information.

Nameserver change | v Some DNS caches still contain old information | v Cache expires | v Current information is requested

This is part of what people commonly refer to as DNS propagation.

// glue

What are glue records?

Consider this configuration:

Domain: example.com Nameserver: ns1.example.com

DNS needs to locate ns1.example.com before it can ask that nameserver about example.com.

This can create a circular dependency.

A parent DNS zone can therefore provide IP-address information for the nameserver. This information is commonly called glue.

// subdomains

Subdomains can use different nameservers

DNS delegation does not have to stop at the main registered domain.

A subdomain can be delegated to another set of nameservers.

example.com | v Nameservers A api.example.com | v Nameservers B

This can be useful when different systems or teams manage different parts of a domain.

// mental model

The easiest way to remember it

Domain = the name Nameserver = where authoritative DNS answers come from DNS records = the instructions IP address = a network destination Hosting = where the website or service runs

A nameserver therefore does not usually store your website. Its job is to provide the DNS information needed to locate the services associated with your domain.

// summary

Nameservers provide the DNS answers.

A nameserver is a DNS server. In domain management, the term usually refers to an authoritative nameserver that provides the official DNS records for a domain or DNS zone. NS records identify nameservers, while DNS delegation tells the wider DNS system which nameservers are responsible for answering questions about a zone.

// networking

What Is DNS?

DNS is the system that connects human-readable domain names to the servers and services behind them. Without DNS, using the web would usually require remembering numerical network addresses instead of names such as freelancecoder.uk.

// definition

DNS means Domain Name System

DNS, or the Domain Name System, is a distributed system used to translate domain names into information that computers can use to locate internet services.

// basic idea

Domain name to server

People prefer names. Computers ultimately need network addresses and routing information.

Domain name | v DNS lookup | v IP address or another DNS destination | v Server | v Website or service

When you enter a domain into a browser, DNS helps determine where the request should be sent.

// example

A simple DNS lookup

Imagine that a browser needs to open:

www.example.com

The browser needs to determine which server or service is responsible for that hostname.

www.example.com | v DNS | v Destination | v Web server

Once the destination has been found, the browser can begin communicating with the appropriate server.

// distinction

Domain, DNS and hosting are different

Domain

The human-readable name, such as example.com.

DNS

The system that tells computers where services associated with that name can be found.

Hosting

The server or platform that stores and serves the website or application.

Website

The actual pages, files and application content that visitors interact with.

Domain | v DNS | v Hosting | v Website

// records

Common DNS record types

DNS stores different kinds of information in DNS records.

A

Maps a hostname to an IPv4 address.

AAAA

Maps a hostname to an IPv6 address.

CNAME

Makes one hostname an alias of another hostname.

MX

Identifies the mail servers responsible for receiving email for a domain.

TXT

Stores text information. TXT records are commonly used for domain verification and email-related policies.

NS

Identifies the authoritative nameservers responsible for a DNS zone.

// A record

Pointing a domain to an IPv4 address

An A record maps a hostname directly to an IPv4 address.

example.com | v A record | v 203.0.113.10

The exact IP address will depend on the server or hosting platform being used.

// CNAME

Pointing one hostname to another

A CNAME record creates an alias between hostnames.

www.example.com | v CNAME | v hosting.example.net

The DNS system can then continue resolving the destination hostname.

Important: a CNAME points to another hostname, not directly to an IP address.

// email

DNS also controls email routing

DNS is not only used for websites.

MX records tell other mail systems which servers should receive email for a domain.

person@example.com | v DNS MX lookup | v Mail server | v Mailbox system

This is why changing website hosting does not necessarily mean changing email hosting.

// nameservers

What are nameservers?

Nameservers are DNS servers responsible for providing information about domains and DNS zones.

A domain registrar may allow you to select which nameservers are authoritative for your domain.

Domain | v NS records | v Authoritative nameservers | v DNS records

Those authoritative servers contain or serve the DNS records that describe where the domain's services should go.

// hierarchy

DNS is hierarchical

Domain names are organised into levels.

www.example.com www = hostname / subdomain example = registered domain label com = top-level domain

At the very top of DNS is the DNS root.

DNS root | v .com | v example.com | v www.example.com

Terminology: people sometimes informally call example.com the "root domain", but in DNS terminology the actual DNS root is the top of the global DNS hierarchy.

// resolution

How DNS resolution works

A DNS lookup can involve several different systems.

Browser | v DNS resolver | v DNS hierarchy | v Authoritative nameserver | v DNS answer | v Browser

A recursive resolver performs or coordinates the lookup required to obtain the answer for the client.

// caching

DNS answers can be cached

DNS systems often cache previous answers so that every lookup does not have to repeat the full resolution process.

This improves speed and reduces unnecessary DNS traffic.

// TTL

What is TTL?

DNS records commonly include a value called TTL, meaning Time To Live.

TTL tells DNS caches approximately how long a record may be retained before it should be refreshed.

TTL = 3600 3600 seconds = 1 hour

A DNS change may therefore not appear everywhere immediately because some systems may still have an older answer cached.

// propagation

What does DNS propagation mean?

When people say that DNS is propagating, they usually mean that different DNS resolvers and caches are gradually replacing previously cached information with newer records.

Old DNS record | v DNS record changed | v Some caches still contain old answer | v Caches expire and refresh | v New answer becomes widely visible

The term "propagation" is convenient, although much of the delay is actually caused by caching and TTL behaviour.

// URL

DNS does not resolve an entire URL

Consider:

https://www.example.com/articles/dns

DNS is primarily concerned with the hostname:

www.example.com

The rest of the URL is handled by the web request and the server or application.

// IP

DNS and IP addresses

DNS and IP addresses solve different parts of the problem.

Concept	Purpose
Domain name	Human-readable name.
DNS	Resolves names and provides service information.
IP address	Network address used for routing traffic.
Server	Handles requests and provides a service.

// practical

When would you edit DNS?

You may need to change DNS records when:

Connecting a website

Pointing a domain to Blogger, WordPress, a hosting company or another web platform.

Configuring email

Adding MX and other email-related records.

Verifying ownership

Adding a TXT or CNAME record to prove control of a domain.

Creating subdomains

Connecting names such as blog.example.com or api.example.com to services.

// mental model

A useful way to remember DNS

Domain = name DNS = directions IP address = network address Hosting = where the service runs Website = what the visitor sees

DNS acts as the connection between the name people type and the internet service that should receive the request.

// summary

Names need directions.

DNS stands for Domain Name System. It connects domain names with the servers and services behind them using records such as A, AAAA, CNAME, MX, TXT and NS. DNS is separate from the domain itself, the hosting platform and the website content, but it is the system that connects those pieces together.

// blogging platforms

What Is Blogger?

Blogger is Google's hosted blogging platform. It allows users to create and publish blogs without having to configure their own web server or install a separate content management system.

// definition

Blogger is a hosted publishing platform

Blogger is an online service for creating, managing and publishing blogs.

Google operates the underlying platform and hosting infrastructure, while the blog owner manages the posts, pages, design and settings.

This means a user can publish a website without manually maintaining their own web server.

// simple model

Blogger combines publishing and hosting

Write content ↓ Blogger ↓ Google infrastructure ↓ Published website

Much of the technical hosting infrastructure is handled by the platform automatically.

// blogspot

Blogger sites can use a Blogspot address

A new Blogger site can be given an address such as:

example.blogspot.com

The blogspot.com domain is used for Blogger-hosted blog addresses.

// blogger vs blogspot

Blogger and Blogspot are not quite the same thing

Blogger

The publishing and website management platform.

Blogspot

The domain commonly used for Blogger-hosted website addresses.

Blogger ↓ Publishing platform Blogspot.com ↓ Default blog domain

// custom domains

Blogger can use your own domain

A Blogger site does not have to remain on a .blogspot.com address.

A separately registered domain can be connected to the Blogger site.

Before: myblog.blogspot.com After: www.mywebsite.com

The content can remain hosted through Blogger while visitors use the custom domain.

// dns

Custom domains are connected using DNS

Blogger provides DNS information that must be added at the provider managing the domain's DNS records.

A typical configuration includes a CNAME for the website hostname.

www ↓ CNAME ↓ ghs.google.com

Blogger also provides a second verification CNAME associated with the particular blog and Google account.

// root domain

Blogger normally uses a subdomain for a custom domain

A Blogger custom domain is normally configured using a hostname such as:

www.example.com

rather than using only:

example.com

The root domain can then be configured to redirect visitors to the www address.

// example architecture

A custom Blogger site can work like this

example.com ↓ DNS ↓ www.example.com ↓ Blogger ↓ Google hosting infrastructure

The domain can be registered with one company while Blogger hosts the website.

// domain + blogger

Blogger does not have to own your domain

Your domain can be registered through a separate registrar.

Domain registrar ↓ DNS records ↓ Blogger ↓ Website

This keeps domain registration and website hosting as separate components.

// https

Blogger supports HTTPS

Blogspot addresses use HTTPS automatically.

Blogger also supports HTTPS for properly configured custom domains.

http://example.com ↓ https://example.com

HTTPS encrypts communication between the visitor's browser and the website.

// posts

Posts are the main publishing unit

Blogger is designed around publishing posts.

Blog │ ├── Post 1 ├── Post 2 ├── Post 3 └── Post 4

Posts can contain text, images, links, HTML and other content.

// pages

Blogger also supports standalone pages

Pages are useful for content that is not primarily part of the chronological blog feed.

About Contact Services Privacy Policy All Posts

// posts vs pages

Posts and pages have different purposes

Posts	Pages
Usually part of the blog feed	Standalone content
Normally date-based	Usually more permanent
Useful for articles	Useful for About or Contact content

// editor

Blogger includes a post editor

Content can be created through Blogger's editing interface.

Users can work visually or edit the HTML representation of post and page content.

Write post ↓ Add formatting ↓ Add images ↓ Edit HTML if required ↓ Publish

// html

Blogger allows direct HTML

Blogger can be useful for people who want a simple publishing platform but still want access to HTML.

<h2>My Heading</h2> <p> My article content. </p>

More advanced page designs can therefore be created without completely replacing the Blogger platform.

// css

Blogger themes can be customised with CSS

.post-body { font-size: 18px; line-height: 1.7; }

CSS can change colours, fonts, spacing, layouts and many other aspects of the design.

// javascript

JavaScript can add additional behaviour

Custom code can be used to add interactive behaviour to Blogger pages and themes.

HTML + CSS + JavaScript ↓ Custom Blogger experience

This allows Blogger to be extended considerably beyond a basic text blog.

// themes

Themes control the appearance of a Blogger site

Blogger provides themes that determine much of the layout and styling of the site.

Typography Colours Columns Header Sidebar Post Layout

// theme code

Blogger themes can also be edited directly

Blogger provides access to the theme's HTML.

This allows advanced users to modify the site's underlying template and add custom HTML, CSS or supported scripts.

Theme editing gives Blogger considerable flexibility. It is possible to make a Blogger site look very different from the default themes when custom code is used.

// gadgets

Blogger uses gadgets for page components

Gadgets can add sections to the site's layout.

Pages Labels Blog Archive Profile HTML / JavaScript

Gadgets can normally be positioned through Blogger's Layout interface.

// labels

Posts can be organised with labels

Blogger labels act as categories or tags for grouping related articles.

Post: What Is JSON? Labels: JSON APIs Data Programming

Visitors can then browse posts associated with a particular label.

// archive

Blogger maintains a post archive

Published posts have dates and can be organised chronologically.

2026 │ ├── September │ ├── What Is HTML? │ ├── What Is CSS? │ └── What Is JavaScript? │ └── August └── Earlier posts

// feeds

Blogger provides blog feeds

Blogger can expose published content through feeds.

These feeds can be useful for:

RSS Readers Atom Feeds Automation Post Indexes Integrations

// automation

Blogger content can be used programmatically

Feeds and APIs make it possible for software to retrieve Blogger content.

Blogger posts ↓ Feed / API ↓ JavaScript ↓ Automatic post index

This is how an automatically populated All Posts page can be created without manually updating the list every time a new article is published.

// hosting

Blogger includes web hosting

A Blogger user does not normally need to purchase separate traditional web hosting for the Blogger site.

You manage: content design domain settings Google manages: Blogger platform hosting infrastructure

This is one of Blogger's most important characteristics.

// hosted platform

Blogger is different from running your own server

Blogger	Self-hosted website
Hosting infrastructure managed for you	You arrange hosting
Built-in publishing system	You choose or build the software
Platform controls server environment	Potentially greater server control
Simple administration	Can require more administration

// blogger vs wordpress

Blogger and WordPress take different approaches

Blogger	WordPress
Google-hosted publishing platform	Content management system
Hosting built into the service	Can be hosted by many providers
Theme and gadget system	Theme and plugin ecosystem
Designed around straightforward publishing	Can support much broader application structures

WordPress.com is a hosted WordPress service, while the WordPress software itself can also be hosted elsewhere.

// advantages

Why might someone use Blogger?

Hosting Included

The site does not require a separately configured traditional hosting account.

Simple Publishing

Posts and pages can be created through a web interface.

Custom Domains

A separately registered domain can be connected.

Code Access

HTML, CSS and theme code can be customised.

// limitations

Blogger is not a general-purpose server platform

Blogger gives substantial control over content and front-end presentation, but it does not give the site owner the same server-level control as a VPS or self-managed hosting environment.

You cannot simply install any server-side software you want inside Blogger.

Blogger supports: HTML CSS JavaScript Posts Pages Themes Gadgets Feeds Blogger is not: A VPS A PHP server A general-purpose database server

// uses

What can Blogger be used for?

Blogs Educational Sites Technical Articles Personal Websites Small Business Content Tutorials Documentation Affiliate Content

// mental model

The simplest way to think about Blogger

Google account ↓ Blogger ↓ Posts + pages + theme ↓ Google-hosted website ↓ Blogspot address or Custom domain ↓ Visitors

// summary

Publish without managing the server.

Blogger is Google's hosted blogging and publishing platform. It provides website hosting, posts, pages, themes, gadgets, feeds, HTTPS and support for custom domains. Users manage the content and design while Google operates the underlying Blogger infrastructure.

// websites

What Is Web Hosting?

Web hosting is the infrastructure that makes a website available on the internet. A hosting provider supplies the computing resources needed to store, run and serve website content to visitors.

// definition

Hosting is where a website runs

Web hosting is a service that provides server resources for websites and web applications.

These resources can include storage, processing power, memory, networking, databases and software.

When someone visits a website, the hosting system delivers the required content to their browser.

// simple model

A website needs somewhere to live

Website files ↓ Web hosting ↓ Internet ↓ Visitor's browser

Without hosting or some equivalent server infrastructure, the website files may exist on a computer but would not normally be publicly accessible to internet users.

// server

Hosting normally involves servers

A server is a computer or software system that responds to requests from other computers.

For a website, a web server may receive a request such as:

GET /about

It can then return the appropriate HTML, CSS, JavaScript, images or generated content.

// request

What happens when someone visits a website?

User enters domain ↓ DNS finds destination ↓ Browser connects to hosting server ↓ Browser requests page ↓ Server processes request ↓ Server returns content ↓ Browser renders website

This process can happen in a fraction of a second.

// domain vs hosting

A domain and hosting are different

A domain is the human-readable internet name.

Hosting is the infrastructure that serves the website.

freelancecoder.uk ↓ Domain name Web server / platform ↓ Hosting

You can buy a domain without buying hosting. You can also move a website to different hosting while keeping the same domain.

// important distinction

Hosting is not the website itself

Website

The pages, code, images, content and application logic.

Hosting

The infrastructure used to store or run that website.

Domain

The name people use to reach the website.

DNS

The system that connects the name to the service.

// static hosting

Some hosting simply serves files

A static website may consist primarily of:

index.html styles.css script.js logo.png

The hosting platform can send these files directly to visitors.

No server-side programming language necessarily needs to run for every page request.

// dynamic hosting

Dynamic websites can run application code

More complex hosting can execute code before producing the response.

Browser request ↓ Web server ↓ PHP / Python / Node.js ↓ Database ↓ Generated HTML or JSON ↓ Browser

This allows a website to generate different content depending on users, data and application logic.

// storage

Hosting provides storage

A website may need space for:

HTML CSS JavaScript Images Videos Documents Databases Backups

// resources

Hosting also provides computing resources

Resource	Purpose
CPU	Processes application instructions
RAM	Temporary working memory
Storage	Stores website files and data
Bandwidth	Transfers data across the network
Database	Stores structured application data

// shared hosting

What is shared hosting?

Shared hosting places multiple customers or websites on the same underlying server infrastructure.

Server │ ├── Website A ├── Website B ├── Website C └── Website D

Resources are shared between multiple hosted sites.

This can make shared hosting inexpensive and simple, although it normally offers less isolation and control than dedicated environments.

// vps

What is VPS hosting?

VPS stands for Virtual Private Server.

Virtualisation divides physical server resources into separate virtual environments.

Physical Server │ ├── VPS 1 ├── VPS 2 ├── VPS 3 └── VPS 4

A VPS generally gives the customer more control over the server environment than ordinary shared hosting.

// dedicated server

What is dedicated hosting?

Dedicated hosting gives one customer access to an entire physical server or dedicated hardware environment.

It can provide substantial control and predictable resources but is generally more expensive and requires greater technical management.

// cloud hosting

What is cloud hosting?

Cloud hosting uses computing resources provided through larger distributed cloud platforms.

Instead of thinking only in terms of one physical server, applications can use virtual machines, databases, object storage, load balancers, serverless functions and other cloud services.

Application │ ├── Compute ├── Database ├── Storage ├── CDN └── Networking

// managed hosting

Managed hosting reduces administration

With managed hosting, the provider handles more of the technical infrastructure.

Server Updates Security Backups Monitoring Performance

The exact level of management depends on the provider and hosting plan.

// hosted platforms

Some platforms include hosting automatically

Services such as blogging platforms and website builders often hide much of the hosting infrastructure from the user.

Create website ↓ Platform stores content ↓ Platform runs servers ↓ Platform serves website

The site owner can concentrate on the website while the platform manages most of the underlying hosting.

// blogger example

Blogger includes hosting

A Blogger site does not require you to rent and configure your own web server.

Google operates the hosting infrastructure while the site owner manages the posts, pages, template and domain configuration.

Custom domain ↓ DNS ↓ Blogger ↓ Google hosting infrastructure

// wordpress

WordPress can be hosted in different ways

WordPress software can run on many hosting providers.

A managed WordPress platform may handle most server administration automatically, while self-managed WordPress hosting can give the site owner much more control over the environment.

// web server software

Hosting may run web server software

Common web server technologies include:

Apache Nginx Caddy IIS

These systems can receive HTTP requests and return website content to users.

// database hosting

Dynamic websites often need a database

Website ↓ Application code ↓ Database

A hosting plan may provide databases such as MySQL or PostgreSQL, or the database may run on a completely separate service.

Smaller applications may also use file-based databases such as SQLite.

// https

Hosting often provides HTTPS support

Modern websites generally use HTTPS to encrypt communication between the website and its visitors.

Browser ⇅ Encrypted HTTPS connection ⇅ Hosting server

Many modern hosting platforms can automatically issue, install and renew SSL/TLS certificates after a domain has been connected correctly.

// bandwidth

Hosting transfers data to visitors

Every time someone loads a page, data travels from the hosting infrastructure to their device.

HTML CSS JavaScript Images Fonts Video API responses

This data transfer is commonly described in terms of bandwidth or traffic.

// cdn

A CDN can work alongside hosting

CDN stands for Content Delivery Network.

A CDN can cache copies of website resources on servers in multiple locations.

Origin hosting ↓ CDN network ↙ ↓ ↘ London Paris New York

Visitors may receive cached resources from infrastructure closer to them rather than retrieving everything directly from the origin server.

// uptime

Hosting affects website availability

If the hosting infrastructure becomes unavailable, visitors may be unable to reach the website even though the domain itself still exists.

Domain working + DNS working + Hosting unavailable ↓ Website unavailable

Domain registration and website availability are therefore separate issues.

// backups

Backups are an important part of hosting

Websites can contain code, images, databases, user content and configuration that may be difficult to recreate.

Good hosting arrangements should consider how that information can be backed up and restored.

// email

Website hosting and email hosting can be separate

A domain can send website traffic to one provider while email is handled by another.

example.com │ ├── Website │ → Web host │ └── Email → Mail provider

DNS records determine which services handle each type of traffic.

// self-hosting

You can technically host a website yourself

A computer connected to the internet can potentially run web server software and serve a website.

However, public hosting requires consideration of networking, security, reliability, backups, power, software updates and availability.

For this reason, most public websites use specialist hosting infrastructure.

// hosting types

Common hosting models

Type	Basic idea
Shared	Multiple websites share infrastructure
VPS	Virtual server environment
Dedicated	Dedicated server resources
Cloud	Resources delivered through cloud infrastructure
Managed	Provider handles more administration
Static	Primarily serves pre-built files

// mental model

The web stack becomes easier to understand

Domain ↓ DNS ↓ Hosting ↓ Web server / application ↓ HTML + CSS + JavaScript ↓ Browser

Each layer performs a different job.

// summary

The infrastructure behind the website.

Web hosting provides the server resources and network infrastructure needed to make websites available on the internet. The domain gives the website a name, DNS directs requests, and the hosting environment stores or runs the website and delivers its content to visitors.