The technology behind the web: how a page is fetched

When you enter an address in the browser, the following steps occur:

1. Your device asks a name server (DNS) where the address is located. It receives an IP address, which acts as a unique phone number for the computer.
2. Your device establishes a connection to that computer, a server, and requests the content.
3. The server sends back data in the form of text, images, and code.
4. Your browser interprets the code and renders the page on the screen.

The process usually takes less than a second, and data flows via fibre-optic cables, sometimes under the sea.

Simulation of network flow: Imagine three roles in a collaboration: an employee (browser), a receptionist (DNS), and an archive (server).

• The employee asks the receptionist: «Which room is the customer data department in?»
• The receptionist replies: «Room 12».
• The employee goes to room 12 and asks for a specific report.
• The archivist in room 12 retrieves the document and hands it over.

Test scenarios where the archivist is not present (the server is down). In that case, the employee gets no response and sees an error message. Also test if the receptionist gives the wrong room number (DNS error). Then the employee ends up at the wrong department. Both errors occur in practice.

An AI service works similarly: your query is sent to a server, which processes the information and sends back a response.