Web Technologies & .NET

DSSSB TGT CS — Section B P2 (Rank ~10). Focus: HTML/CSS/JS basics, HTTP, ASP.NET/.NET keywords, servers.

1. WWW, URL, HTTP, HTTPS

Term	Meaning
WWW	World Wide Web — hypertext system over the Internet
URL	Uniform Resource Locator — address of a resource
HTTP	HyperText Transfer Protocol — request/response for web
HTTPS	HTTP + TLS/SSL encryption

URL parts (typical): protocol://host:port/path?query#fragment

HTTP methods (exam): GET (retrieve), POST (submit), also PUT/DELETE.
Default ports: HTTP 80, HTTPS 443.
Trap: Internet ≠ WWW. WWW is a service on the Internet.

2. HTML Essentials

Skeleton:

html

<html>
  <head><title>Page</title></head>
  <body>...</body>
</html>

Tag	Role
`html`	Root
`head`	Metadata, title, CSS/JS links
`body`	Visible content
`title`	Browser tab title (in head)
`a`	Hyperlink (`href`)
`img`	Image (`src`, `alt`)
`table`, `tr`, `td`, `th`	Tables
`form`	Input container (`action`, `method`)
`input`	Form control (`type`: text, password, submit, checkbox…)
`p`, `h1`–`h6`, `br`, `div`, `span`	Structure/text

Empty/void tags historically: img, br, hr, input.
Trap: <title> does not display in page body.

3. CSS

Type	How
Inline	`style="..."` on element
Internal	`<style>` in `head`
External	`.css` file via `<link>`

Selectors (basic): element (p), class (.box), id (#main), descendant (div p).

Box model: content → padding → border → margin.

Cascade + specificity: inline > id > class > element (simplified exam view).
External CSS preferred for reuse/maintenance.

4. JavaScript Basics

Client-side scripting in browsers (also server via Node — awareness).
Variables: var (legacy), let, const.
Types: number, string, boolean, object, etc.
Can react to events (click, load, submit).

DOM (Document Object Model): tree representation of HTML; JS can read/change elements, styles, content.

document.getElementById("demo").innerHTML = "Hi";

5. XML vs HTML

	HTML	XML
Purpose	Display web pages	Store/transport structured data
Tags	Predefined	User-defined
Case	Not strict (HTML5)	Case-sensitive
Closing	Some optional historically	Must be well-formed
Focus	Presentation	Data description

Both can look similar (tags); XML is stricter/well-formed.
XHTML = HTML as XML application (older exam mention).

6. Cookies vs Sessions

	Cookies	Sessions
Stored	Client (browser)	Server (session id often in cookie)
Size	Small limits	Can hold more server-side
Security	Visible/modifiable by user	Safer for sensitive data
Lifetime	Expiry settable	Ends on timeout/logout typically

Used for login state, preferences, cart.
Trap: Cookie alone is not secure storage for passwords.

7. ASP.NET / .NET Stack (keywords)

Term	Idea
.NET	Microsoft development platform
ASP.NET	Web framework on .NET for dynamic sites/APIs
CLR	Common Language Runtime — execution engine
CTS	Common Type System — shared type rules across languages
CLS	Common Language Specification — interop subset
JIT	Just-In-Time compiler — IL → native code at runtime
MSIL / IL	Intermediate Language from compilers
Managed code	Runs under CLR

Pipeline idea: Source → Compiler → IL → JIT → Native execution.

ASP.NET Web Forms / MVC / Core — names appear in exams; Core = cross-platform evolution.

8. Web Servers

Server	Notes
IIS	Internet Information Services — Microsoft Windows
Apache	Popular open-source HTTP server
Others	Nginx, Tomcat (Java servlets — awareness)

Role: listen for HTTP requests, return pages/resources, run server-side apps.

9. Client–Server & Page Types

Concept	Idea
Client	Browser / app requesting
Server	Host providing resources/apps
Static page	Same HTML file returned (no server computation per request)
Dynamic page	Generated/processed on server (ASP.NET, PHP, JSP…) using DB/logic

Thin client vs fat client (exam vocabulary).
3-tier: presentation → application → data.

Quick Revision Traps

HTTPS = encrypted HTTP (port 443).
title in head; visible headings use h1… in body.
CSS box: margin outside border; padding inside border.
XML = data; HTML = display.
Sessions mainly server-side; cookies client-side.
CLR runs managed .NET code; JIT compiles IL.
IIS ↔ Microsoft; Apache ↔ common open-source.
Static = fixed file; dynamic = generated response.

Web Technologies & .NET ​

1. WWW, URL, HTTP, HTTPS ​

2. HTML Essentials ​

3. CSS ​

4. JavaScript Basics ​

5. XML vs HTML ​

6. Cookies vs Sessions ​

7. ASP.NET / .NET Stack (keywords) ​

8. Web Servers ​

9. Client–Server & Page Types ​

Quick Revision Traps ​