01-26-2022-notes

		            HTML 
	            [Hyper Text Markup Language]

- The term "Hyper" means "Beyond"
- Hyper Text comprises of content beyond what you see.
- Markup is general computer term derived from "Marking Up"
- Markup language is a language used for presentation.
- It is used for presenting on Browser. 

Evolution:
- The first Markup language used for Internet was GML built by CERN
- After GML [Generic Markup Language] - We use SGML [Standard]
- 1990's "Tim Berner Lee" introduced the concept of "Web" & HTML.
- HTML is superset to GML and SGML.
- IETF Group started developing HTML  upto 3.2
- 2004 W3C and WHATWG  started developing HTML 
   World Wide Web Consortium 
   Web Hyper Text Application Technology Work Group
- HTML Version 4, 
- HTML Latest Version 5.  [2014]

		       Browser Architecture
		       ================
Markup => Bytes => Chars => Token => Elements => DOM => Layout => Render => Paint

HTML is a collection of Elements arranged in a Hierarchy called DOM.
[Document Object Model]

HTML Elements are classified into 5 Groups
1. Normal Elements
2. Void Elements
3. RC Data Elements
4. Raw Text Elements
5. Foreign Elements

Normal Elements:
- It returns a presentation directly on call back.
- It doesn't require additional attributes.
- It starts but can't stop implicitly.
- You have to stop explicitly by using end token.

      start tag	<b>
      end tag	</b>

Void Elements:
- The term void means no return value.
- It will not paint anything. [Empty]
- It will paint only content asked to.
- Doesn't require end tag

    <img>
 
RC Data Elements
- Rich Content Data Elements

<textarea>

Raw Text Elements


Foriegn elements

   SVG, MathML, Canvas

HTML Page Structure: