What is XML, DTD, and XSLT

All these letters, abbreviations, meanings and so forth. What do they all mean and how do we use them? Here are some basics breakdown :

First we will start at the top. The VERY top. SGML stands for Standard Generalized Markup Language. Simply put, it is the very root coding of coding. HTML is an application of SGML.

XML is a simplified subset of SGML. It stands for eXtensible Markup Language.

DTD stands for Document Type Declaration. It is a set of instructions that states what tags are usable and what (re)action they create. Each browser has a DTD set in it's programming set by the browser companies. This is how some tags will work in only one type of browser or version. It has the tags stated in it's DTD. XML makes it possible to create unique tag sets by applying it's own DTD. This makes the DTD more compatible with more browsers.

XSLT stands for eXtensible Stylesheet Language Transformation. It is a strong versions of CSS that formats the XML page for viewing.