L01. How computers learned to communicate

You will open a website by its address and explain how the Web differs from the internet. Allow about 30 minutes. Prepare a connected computer or phone, a browser — a program for viewing websites — and paper for notes. No account is needed.

In class

The teacher opens a page by its address and points out the address bar. Together, trace the request from device to server and explain which connection Wi-Fi provides.

Connecting machines first

Olena wants to show friends her organised desk. Sending a photo link relies on several inventions: transmitting data, shared communication rules and linked pages.

In 1969, ARPANET connected its first research computers in the United States, reaching four by December. Information travelled in small pieces called packets. Messages could share communication channels, with the receiving end reconstructing the data. [F204]

Universities and organisations built their own networks. Exchanging data between them required agreed rules, called protocols. ARPANET’s switch to TCP/IP on 1 January 1983 was a milestone. The internet connected networks; it was never one enormous computer. [F204]

Connecting documents next

Exchanging data did not yet make documents convenient to read. In 1989, Tim Berners-Lee at CERN proposed a system of linked documents. By the end of 1990, its first browser and web server — a program supplying pages — were running. CERN made Web software freely available in 1993, helping it spread. [F205]

The internet carries data between devices. The Web, short for World Wide Web, provides linked pages that you open in a browser. Email also uses the internet, but it is not simply another name for the Web. When you read email on a website, the page provides a convenient window into an email service.

Home connections gradually made the network part of everyday life; smartphones brought access beyond the desk. Pages became interactive: a browser now lets you edit a document, watch a video or talk to AI. A remote computer does work and sends back the result. A computer or program responding to requests is called a server. The “cloud” means remote computing and storage; data still resides on physical equipment.

Wi-Fi connects your device to a local network. An internet service provider is the company supplying the onward connection. A website request passes through intermediate devices before reaching its server.

[[VIS:f5_internet_path]]

Trace the route yourself

• Open a browser. Click the address bar at the top of its window, rather than a search box inside a page.
• Type https://example.com and press Enter. We will use this example address when explaining websites.
• Look at the page title and its address. Save the address in a note or write it on paper.
• Open another familiar website. If one address will not open, trying another helps you check whether the problem concerns only the first site.

> [RESULT] A simple page headed Example Domain should appear. You reached it by entering its address, without searching.

> [FIX] You see a Wi-Fi symbol, but pages will not open. Try another website, then check the connection on another device you own. Wi-Fi can work even when the provider’s external connection is unavailable.

Home practice

• Choose two familiar websites, such as your library and local transport service. Open them by entering their addresses. If you do not know an address, find the official site first, then copy it from the address bar.
• On a sheet headed “My two addresses”, record each site’s name, address and purpose. Reopen both using your notes. The check passes when the intended pages appear.

Self-test

• Are the Web and the internet the same?
• Your phone shows Wi-Fi, but two sites will not open. Does the symbol prove that internet access is working?
• What happened in 1989?

Words you will need

• Browser: a program that opens web pages.
• Protocol: agreed rules for exchanging data.
• Server: a program or computer that handles requests.
• Link: an element in a page or message that opens another resource when selected.