HTML stands for HyperText Markup Language. Its a type of text document, where text is marked up by using special tags that inform a program that reads the text in how to render the text. Typically that program is a Web Browser such as Internet Explorer, FireFox, Opera or Chrome.
Heres an example of a very simple HTML document
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<title>My First HTML Page</title> </head>
My text goes here.