Topic 5 · The internet and its uses

The internet and the World Wide Web

The difference between the internet and the web, URLs, HTTP and HTTPS, how a browser finds a page with DNS, cookies, and digital currency.

Lesson 1 of 2Syllabus 5.1, 5.2updated October 31, 2026

Internet versus World Wide Web

The internet is the infrastructure: a huge global network of connected computers, cables, and routers.

The World Wide Web is a collection of web pages and other resources that you reach using the internet. Email, online games, and video calls also use the internet but are not part of the web.

Parts of a URL

A uniform resource locator (URL) is a text address for a web page. It has three main parts:

https://

www.pseudoeditor.dev

/docs/loops

https://: Protocol: the rules used to transfer the page.
www.pseudoeditor.dev: Domain name: the website's server.
/docs/loops: File name / path: the page on that server.

HTTP and HTTPS

HTTP (hypertext transfer protocol) is the set of rules for sending web pages between a server and a browser.

HTTPS is HTTP made secure with SSL/TLS. The data is encrypted, and the server proves its identity with a digital certificate, so data such as passwords and card numbers cannot be read if intercepted. Browsers show a padlock for HTTPS sites.

What a web browser does

A browser is application software that requests and displays web pages. It:

renders HTML into the page you see
stores bookmarks, favourites, and history
lets you open several pages in tabs
stores cookies
provides navigation: back, forward, refresh, and an address bar

How a page reaches your screen

Computers find each other by IP address, but people type domain names. The Domain Name System (DNS) translates one into the other.

From URL to page

1
Type the URL
The browser needs the IP address for the domain name.
2
Ask a DNS server
The browser sends the domain name to a DNS server.
3
Find the IP address
If that DNS server does not know it, it asks other DNS servers.
4
Return the IP address
The IP address is sent back to the browser.
5
Request the page
The browser sends a request to the web server at that IP address.
6
Render the page
The server sends the HTML back and the browser displays it.

Cookies

A cookie is a small text file that a website stores on your computer through the browser. It lets the website remember you.

	Session cookie	Persistent cookie
Stored	In memory, only while the browser is open	On the device, until it expires or is deleted
Used for	Keeping items in a shopping basket as you browse	Remembering logins, language, and preferences; tracking for adverts

Digital currency and blockchain

A digital currency exists only electronically. Cryptocurrencies such as Bitcoin are not controlled by a bank or government. Instead, every transaction is recorded on a blockchain.

A blockchain is a digital ledger shared across many computers. Each block holds transactions plus a hash of the previous block, chaining them together. Changing an old block would break every block after it, and every copy of the ledger would disagree, so tampering is easy to spot.

Key terms

Internet: A global network of interconnected computer networks.
World Wide Web: A collection of websites and web pages accessed using the internet.
URL: A text address that identifies a web page.
DNS: Domain Name System: translates domain names into IP addresses.
Cookie: A small file stored by a website on a user's device to remember information.
Blockchain: A shared digital ledger of transactions where each block links to the previous one.

Check yourself

Explain the difference between the internet and the World Wide Web.Show answer

The internet is the global network infrastructure. The web is the collection of web pages accessed using it.

Identify the protocol and domain name in https://www.example.com/news/today.Show answer

Protocol: https. Domain name: www.example.com.

What does a DNS server do?Show answer

It looks up the IP address that matches a domain name and returns it to the browser.

Why does HTTPS protect a password typed into a website?Show answer

The data is encrypted with SSL/TLS, so if it is intercepted it cannot be understood.

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