This module was written by the W3C, and sets the rules and provides background for the decisions of all the coding for the font sets in HTML and CSS. There is a lot to provide for, as many times fonts have to be adapted to different languages or different alphabets, and you cannot always get a perfect match. In these cases, there is a font specification, but sites have a default form or the generic family available, which allows the appearance to be similar. For aspects such as style, some fonts do not have a specific setting for bold or oblique. But there is a font-synthesis, which allows the weight of the font to be set and then act in place of one of those styles. Font-face (new to CSS since CSS2) is a great system as well, which allows a different font entirely to be put in place for a specific element of a site, specifically an uncommon one which might need to be downloaded from another source for that purpose. Overall it is a really fascinating process through which characters (or glyphs) are translated into a font by the server, and in order to get the exact look across that you want, might take a good deal of planning and coding.
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