what is html ??

HTML stands for Hyper Text Markup Language.

HTML is not a programming language, it is a markup language.

A markup language is a set of markup tags.

HTML uses markup tags to describe web pages.

simple note from me for basic HTML :
HTML Tags
HTML Element Syntax
HTML Documents = Web Pages
HTML Headings, HTML Paragraphs, HTML Links & HTML Image
HTML Line Breaks
HTML Attributes
HTML Lines & HTML Comments
HTML Formatting

for more details click this link :
http://www.w3schools.com/html/default.asp