Recent Web Technologies: A Case Study on WWW

Case Study on WWW (World Wide Web)

1. What is the WWW?

The World Wide Web is a distributed, hypermedia information system on the Internet: documents (web pages) written in HTML, identified by URLs, transferred over HTTP and linked through hyperlinks.

WWW ≠ Internet: the Internet is the network infrastructure; the Web is a service running on it (like e-mail, FTP).
Invented by Tim Berners-Lee (CERN, 1989-91) — HTML, HTTP, URL, first browser (Nexus) and first server (CERN httpd).

2. The Four Pillars of the Web

Pillar	Role	Example
HTML	Structure and presentation of documents	`<h1>`, `<a href>`
HTTP	Stateless request–response protocol between client and server	`GET /index.html HTTP/1.1`
URL / URI	Global naming (addressing) of resources	`https://www.example.com:443/page?id=5`
Browsers & Servers	Client (renders HTML) and server (stores & serves pages)	Chrome, Firefox; Apache, Nginx, IIS

3. URL Structure

 scheme://host:port/path?query#fragment
   |        |    |    |      |      |
 https   example.com 443 /dir/page.html id=5    #top

scheme — protocol (http, https, ftp, mailto)
host — DNS name or IP; port — default 80 (HTTP) / 443 (HTTPS)
path — resource on the server; query — name=value&... parameters
fragment — anchor inside the document

4. Working of the Web — Step by Step

 USER -> BROWSER -> DNS -> WEB SERVER -> BACK END (CGI/PHP/JSP/DB)
  1. User enters a URL / clicks a link
  2. Browser resolves host name via DNS (URL -> IP address)
  3. Browser opens a TCP connection to server:port
  4. Browser sends an HTTP request  (GET /page.html HTTP/1.1)
  5. Server maps URL to a file or program (static page, or script + database)
  6. Server sends an HTTP response (status line + headers + HTML body)
  7. Browser parses HTML; fetches embedded objects (CSS, JS, images)
  8. Browser renders the page; connection may close or persist

5. Static vs Dynamic Pages

Aspect	Static page	Dynamic page
Content	Fixed HTML file	Generated per request by a program
Storage	Plain `.html` on server	Templates + application logic + database
Generation time	At authoring time	At request time (or cached)
Examples	Company brochure, documentation	Search results, shopping cart, e-banking
Technologies	HTML, CSS	CGI, PHP, JSP/Servlet, ASP.NET, Node.js

6. Three-Tier Web Architecture

 TIER 1  CLIENT (browser: HTML/CSS/JS)
              |  HTTP/HTTPS
 TIER 2  WEB + APPLICATION SERVER (Apache/Tomcat: PHP, JSP, Servlets)
              |  SQL / connectors
 TIER 3  DATABASE SERVER (MySQL, Oracle)

Presentation logic stays in the browser, business logic in the middle tier, data in the third tier — the model that made the web scale.

7. Evolution: Web 1.0 → 2.0 → 3.0

Version	Character	Users	Technology
Web 1.0 (read-only)	Static pages, one-way publishing	Consumers	HTML, CGI
Web 2.0 (read-write)	User participation, social media, blogs, wikis	Prosumers (producers)	AJAX, APIs, tagging, RSS
Web 3.0 (semantic)	Machine-understandable data, personalised services	Collaborative intelligence	RDF, OWL, SPARQL, AI

8. Milestones in Web History

Year	Milestone
1989-91	Berners-Lee proposes and builds WWW at CERN (HTML, HTTP, first browser/server)
1993	Mosaic browser ( graphical, popularises the web)
1994-95	Netscape Navigator, IE 1.0; W3 Consortium (W3C) founded
1995	JavaScript, Java applets, CGI-based dynamic content
1997-99	HTML 4.0, CSS, XML 1.0, HTTP/1.1 (RFC 2068/2616)
2004-06	Web 2.0 era — AJAX (Gmail, Google Maps), blogs, wikis, social networks
2010s	Semantic web (RDF/OWL), HTML5, mobile web, HTTPS everywhere
2020s	Web 3.0 / decentralised web, WebAssembly, SPAs, PWAs

9. Exam Points

Explain the architecture and working of the WWW with a diagram — 10 marks (very frequent).
Explain URL structure and the steps between entering a URL and seeing the page — 7 marks.
Difference between WWW and Internet, and static vs dynamic pages — 5 marks.
Trace the evolution of the Web (1.0 → 3.0) with examples — 5-7 marks.