HTML is the "blood" (or data) of the web.
HTML is DATA.... Which means HTML is used to convey information or content. Web Browsers were designed to display this generic information in an understandable manner.
HTML was not intended to provide FORMATTING. Unfortunately, it has been "corrupted" to affect how data is displayed. Web page creation programs like Microsoft Office mangle HTML into an unrecognizable mess (which surprisingly only really works on Microsoft products, like Windows Explorer).
HTML is not a Programming language, though it has some things in common with programming languages, such as a specific syntax (rules on how your "sentences" must be laid out. Again, HTML provides data. Most programming languages provide DATA and control (how to manipulate the data). HTML does not provide this control).