Technically, HTML (HyperText Mark-up Language) is a Standard Generalized Mark-up Language
(SGML) application. Web sites are composed using HTML, which consists of ASCII text and various HTML tags which the browser interprets to format the page. As a Mark-up language, HTML lacks many of the attributes of "real" computer languages -- it's function is pretty much just to format output on a page.
Learning HTML is probably easier if you have a good book on the subject , but ther are plenty of tutorials and references online
The World Wide Web Consortium(W3C) recommends standards for
HTML to ensure uniformity of the language regardless of platform or environment, thus promoting the widest possible readership for WWW sites.