HTML stands for Hyper Text Markup Language and it was developed by Tim Berners-Lee in 1991. HTML is used to create static web pages or a website. HTML is a Markup language means that everything should be written inside the tags. HTML tags are the keyword surrounded by the angle brackets.
HTML is not a case sensitive language, it means that the HTML tags can be written in lowercase or in uppercase. HTML code can be written in any text editor such as Notepad, Notepad++, Dreamweaver, Brackets, Sublime etc, and the output will be displayed on the web browser(Google Chrome, Mozilla Firefox, Opera, Safari etc). HTML tags are divided into two catagories:
Empty tag / Single tag / unpair tag : This type of tags does not contain any other tag or text. They are started and ended in the same line. HTML tag with no content is known as empty tag. Example of empty tags are: <br> , <hr> etc.
Container tag / Double tag / Pair tag : This type of tags have an opening tag, some text and tags enclosed in it and a closing tag. Example of container tags are: <html> </html>, <body> </body> etc.