The Internet, Web Technologies and E-Services
Domain 5 - The Internet, web technologies and e-services
Tests Internet infrastructure, WWW protocols, web development and online service models.
Core rules
- The Internet is interconnected networks; the WWW is a service using URLs, HTTP/HTTPS and HTML.
- DNS resolves domain names to IP addresses; the browser connects via TCP; HTTPS adds TLS encryption.
- Client–server model; static pages are fixed, dynamic pages are generated by server-side code.
- HTML structures content, CSS styles it, JavaScript adds client-side behaviour.
- E-services include e-commerce, e-government, e-learning and e-banking; they need authentication, payment security and accessibility.
Worked example
A user enters https://school.edu/exam.html. The browser asks DNS for school.edu's IP. It opens a TCP connection to port 443, negotiates TLS, then sends an HTTP GET for /exam.html. The server returns HTML; the browser parses it, requests CSS and images, executes JavaScript and renders the page. Reasoning: DNS happens before connection; HTTPS uses port 443 and encryption; HTML is a resource, not the protocol. If the page is dynamic, the server may query a database before composing the response.
Traps
Internet ≠ WWW. HTTP is stateless; cookies and sessions add state. GET puts data in the URL and is not for passwords. A web page is not a website. HTTPS encrypts traffic but does not guarantee a trustworthy site.