Chapter 1

The Web, Browsers, Servers, URL & HTTP

The history of the Web, how browsers render it, how servers deliver it, and the URL/HTTP contract between them.

History of the World Wide Web

Period	Milestone
1989	Tim Berners-Lee invents the Web at CERN and creates the first web page.
1991	First public website goes live; hyperlinks connect documents globally.
1990s	HTML and CSS standards emerge; the browser wars begin.
2000s	Web 2.0: user-generated content, blogs, wikis.
2010s	Mobile-first design; SPA frameworks (React, Vue, Angular).
2020s	AI-generated UIs, Web3 / WebAssembly, edge computing, PWAs.

Web Browsers

A web browser is software that retrieves and renders web content (HTML, CSS, JavaScript) from the Internet, presenting it as interactive pages.

Rendering engine — interprets HTML/CSS/JS (Blink, WebKit, Gecko).
Dev Tools — inspect elements, console, network, performance.
Tab management — isolated browsing contexts, memory per tab.
Privacy mode — incognito with no history or cookies.
Extensions — add-ons that extend functionality.

2025 market share: Chrome ~65%, Safari, Edge ~5%, Firefox ~3%, Others ~8%. AI sidebars (Copilot, Gemini) are now standard.

Web Servers

A web server is software (and hardware) that stores, processes and delivers web content to clients over HTTP/HTTPS. When a browser requests a page, the server processes the request and sends back HTML, images, CSS or JSON.

Key functions

Store and serve static files (HTML, CSS, images)
Run server-side code for dynamic pages
Manage HTTPS encryption and TLS certificates
Handle load balancing across multiple servers
Cache content for performance optimisation

Server	Notes
Apache	Open-source, cross-platform, module-rich (~25%)
NGINX	High performance, reverse proxy, event-driven
Cloudflare	CDN + server, DDoS protection, edge network
Microsoft IIS	Windows-native, ASP.NET optimised
Caddy	Automatic HTTPS, modern config, Go-based
Serverless	AWS Lambda, Vercel, Netlify — no server management

URL & HTTP / HTTPS

A URL (Uniform Resource Locator) points at a resource:

https://www.utem.edu.my/bitm2113/rajah1.png
 scheme   host            path        resource

HTTP request structure

Request line — method + URL + version
Methods — GET, POST, PUT, DELETE, PATCH
Headers — user-agent, content-type
Optional body — form data, JSON payload

Version	Characteristic
HTTP/1.1	One request per connection; persistent keep-alive
HTTP/2	Multiplexing; header compression; binary protocol
HTTP/3	QUIC (UDP-based); faster; ~30% of web traffic (2025)
HTTPS	TLS encryption; mandatory for all modern sites