The internet
The worldwide infrastructure connecting millions of smaller networks. It carries webpages, games, video calls, email, messages, and much more.
1
Internet, web, and Wi-Fi are different
People often use these words as if they mean the same thing, but each describes a different part of the system.
The World Wide Web
A collection of linked pages and resources that use the internet. The web is one service on the internet, invented long after the internet began.
Wi-Fi
A short-range radio connection between a device and a nearby access point. Your internet can also arrive through cables or mobile networks.
2
Meet the important parts
Think of the internet as a delivery system. Addresses identify destinations, routers choose roads, and agreed rules keep every machine understandable.
Device or client
Your tablet, phone, or computer requests information. “Client” means a device or program asking another computer for a service.
Router
A router connects networks and forwards packets toward their destination. Your home router also shares one internet connection among many devices.
ISP
An Internet Service Provider connects your home, school, or phone to the wider internet. Its network connects onward to other networks.
Server
A server is a computer or program that responds to requests. Web servers send page files; game servers coordinate players; mail servers carry email.
Packet
Information is divided into labelled chunks called packets. Packets may take different routes and are put back in order when they arrive.
Protocol
A protocol is an agreed set of communication rules. TCP/IP helps move data; HTTP and HTTPS are used when browsers and web servers communicate.
The internet's address book
DNS turns names into numbers
Computers use numerical IP addresses to find one another. Humans prefer names such as example.com. The Domain Name System, or DNS, looks up the matching address.
A DNS resolver may already remember the answer in a temporary cache. If not, it asks other DNS servers until it finds the correct record.
example.com → DNS lookup → IP address
DNS does not send the whole webpage. It helps your device discover which server to contact.
3
Anatomy of a web address
A URL, or Uniform Resource Locator, tells a browser how and where to request a resource.
https://Protocol: communicate using encrypted HTTPS
www.Subdomain: one named area of the domain
example.comDomain name: the registered, human-friendly name
/science/spacePath: the resource or section being requested
Domain name
A memorable name registered for a period of time. Endings such as .com, .org, .in, and .uk are called top-level domains.
IP address
A network address for a device or connection. IPv4 looks like 192.0.2.1; newer IPv6 provides far more possible addresses.
HTTPS
HTTPS encrypts data between your browser and the website. The padlock protects the connection, but it does not guarantee that a website is honest.
4
What happens after you press Enter?
A page loads through a fast sequence of teamwork. Some steps may be reused or skipped when information is already cached.
- 1
The browser reads the URL
It identifies the protocol, domain, path, and any extra instructions.
- 2
DNS finds an address
The domain is matched to an IP address for a suitable server.
- 3
A secure connection begins
With HTTPS, the browser checks a digital certificate and sets up encryption.
- 4
The browser makes a request
It asks the server for the page, often using an HTTP GET request.
- 5
Packets travel through routers
Routers forward the request and response across connected networks.
- 6
The browser builds the page
HTML supplies structure, CSS controls appearance, and JavaScript adds behaviour.
5
Website, browser, and search engine
These three are related, but they do different jobs.
ThingIts jobExamples
WebsiteA collection of pages and resources under a domain.A school site, encyclopedia, or shop
Web browserAn app that requests, reads, and displays web content.Chrome, Firefox, Safari, Edge
Search engineA service that discovers and indexes pages, then ranks matches for a query.Google, Bing, DuckDuckGo
Typing a complete address into a browser can go directly to a site. Typing topic words into a search engine asks it to suggest pages.
6
More ideas behind every connection
Once you understand the journey of a webpage, these words reveal even more of the system.
Bandwidth and latency
Bandwidth is how much data can move in a time. Latency is the delay before data begins returning. A wide road can still start far away.
The cloud
“Cloud” usually means remote computers and data centres providing storage or processing through a network—not information floating in the sky.
Cookies and cache
Cookies let a site remember small pieces of information. A cache keeps copies of resources so they can load faster next time.
Hyperlinks
Links connect one resource to another. This web of references is why the World Wide Web is called a web.
Undersea cables
Most intercontinental internet traffic travels through fibre-optic cables on the ocean floor. Satellites are important, but do not carry everything.
Data centres and CDNs
Data centres hold many servers. Content delivery networks keep copies closer to users so popular files arrive faster.
7
Be a wise digital citizen
The internet connects real people. Good judgement matters as much as technical knowledge.
Ask a trusted adult before sharing your full name, address, school, location, passwords, or photographs.
A password manager can help families store long passwords. Never share passwords with friends.
Unexpected prizes, urgent threats, strange attachments, and look-alike addresses can be tricks called phishing.
Compare reliable sources, identify the author and date, and look for evidence. Popular does not automatically mean true.
Messages affect real people. Save evidence and tell a trusted adult if something online feels frightening, secretive, or unsafe.
Sleep, exercise, face-to-face time, and device breaks all help your brain and body work well.
8
Quick knowledge check
Open each question only after making your own prediction.
Does Wi-Fi mean the same thing as the internet?
No. Wi-Fi is one way to connect a nearby device to a network. That network may then connect to the internet.
What does a router do?
It forwards packets between networks, choosing the next useful path toward their destination.
Why do we need DNS?
DNS translates memorable domain names into network addresses computers can use.
Can packets from one message take different routes?
Yes. Networks can route individual packets along different paths and reassemble them at the destination.