A network of networks
The internet is a worldwide network that connects billions of computers, phones and devices. It lets us send email, watch videos, play games, video-call and look up information in seconds. More than 5 billion people use it.
The internet and the World Wide Web are not the same thing:
| Internet | World Wide Web |
|---|---|
| The global network of connected computers and cables | A collection of linked web pages that runs on the internet |
| Started in 1969 | Invented in 1989 |
| Carries email, video calls, games, apps and the web | Accessed through a web browser |
How the internet began
| Year | Event |
|---|---|
| 1969 | ARPANET, funded by the U.S. Department of Defense, sends its first message between UCLA and Stanford. The system crashed after two letters, "LO" (for "LOGIN"). |
| 1971 | Ray Tomlinson sends the first network email and uses the @ symbol |
| 1974–1983 | Vint Cerf and Bob Kahn develop TCP/IP, the common language for networks; ARPANET switches to it on January 1, 1983, often called the internet’s birthday |
| 1985 | Domain names like .com and .ca begin |
| 1989 | Tim Berners-Lee at CERN in Switzerland proposes the World Wide Web |
| 1991 | The first website goes online |
| 1993 | Mosaic, an early graphical web browser, makes the web easy to use |
| 1990s–2000s | Search engines, online shopping, social media and Wi-Fi spread |
| 2007 onward | Smartphones bring the internet everywhere |
Canada and the internet
Canada built its own research network, CA*net, in 1990. Canadians helped develop early internet tools: Archie, created at McGill University in 1990, is considered the first internet search engine.
How the internet works
Packets
When you send a photo, it doesn’t travel in one piece. It’s broken into small packets of data. Each packet carries:
- part of the data
- the sender’s address
- the destination address
- a number so packets can be put back in order
Packets may take different routes and arrive out of order. The receiving computer reassembles them. If one goes missing, it’s sent again.
Addresses
Every device on the internet has an IP address, a number like 192.0.2.44. Since numbers are hard to remember, the Domain Name System (DNS) acts like a phone book, translating names like "example.ca" into IP addresses.
The physical internet
The internet isn’t "in the air." It runs on:
- undersea fibre-optic cables that carry most international data as pulses of light
- cables buried under streets
- cell towers and Wi-Fi routers
- satellites, especially for remote areas
- huge data centres full of servers that store websites and services
The World Wide Web
Tim Berners-Lee wanted scientists to share documents easily. He invented:
- HTML: the language for writing web pages
- URLs: web addresses
- HTTP: rules for sending web pages
- the first web browser and web server
He chose not to patent his invention, so anyone could use the web for free.
How the internet changed life
| Area | Change |
|---|---|
| Communication | Email, messaging and video calls connect people worldwide instantly |
| Learning | Online courses, encyclopedias and videos |
| Work | Remote work, online collaboration |
| Shopping and banking | Online stores and payments |
| Entertainment | Streaming music and video, online games |
| Science | Researchers share data and work together globally |
Challenges
| Challenge | Why it matters |
|---|---|
| Privacy | Companies and others collect personal data |
| Misinformation | False information spreads quickly |
| Cybersecurity | Hackers, scams and viruses |
| Online safety | Cyberbullying and inappropriate content |
| The digital divide | Not everyone has fast, affordable internet, including many rural and northern communities in Canada |
| Energy use | Data centres use large amounts of electricity |
Staying safe online
- Use strong, unique passwords.
- Don’t share personal information with strangers.
- Think before you post; online posts can last forever.
- Check sources before believing or sharing information.
- Tell a trusted adult if something online makes you uncomfortable.
Common mistakes
- Thinking the internet and the web are the same.
- Thinking Wi-Fi is the internet. Wi-Fi connects your device to a router, which connects to the internet.
- Thinking data travels mostly by satellite. Most travels through cables.
Try it yourself
- Tear a written message into numbered pieces. Give them to classmates who pass them to a "receiver" by different routes. Reassemble the message, just like packets.
- Find a map of undersea internet cables online. Which ones land in Canada?
- Make a poster with five online safety tips.
Quick recap
- The internet is a global network of networks; the web is a system of linked pages on it.
- It began as ARPANET in 1969 and adopted TCP/IP in 1983.
- Tim Berners-Lee invented the World Wide Web in 1989.
- Data travels in packets using IP addresses, mostly through fibre-optic cables.
- The internet transformed life but brings challenges like privacy and misinformation.