HTML is a language for designing web pages. HTML documents are webpages. Pages created in HTML are used by Web browsers to present text and graphics. HTML uses markup tags such as to designate the beginning of a paragraph, and to indicate its end.
The World Wide Web (WW) or Internet has become an intragal of our working (and playing) world. You cannot spit anymore these days without hitting a URL (if you do not know what a URL is, you will find out here). In a very short time span, the web has revolutionized the way we access information, education, business, entertainment. It has created industries where there were none before.
So if you're hot to make a web page, this is the place to start.