HTML stands for Hypertext Markup Language. HTML is based on the Standard Generalized Markup Language (SGML), a much larger document-processing system. To write HTML pages, you won't need to know a whole lot about SGML. However, knowing that one of the main features of SGML is that it describes the general structure of the content inside documentsrather than its actual appearance on the page or onscreendoes help. This concept might be a bit foreign to you if you're used to working with WYSIWYG (What You See Is What You Get) editors like Adobe's Dreamweaver or Microsoft FrontPage, so let's go over the information carefully.

Cascading Style Sheets as a way you could control the look and feel of your pages. Styles are a way to control how the browser renders HTML tags.CSS provides a lot of flexibility in how you can alter the appearance of any type of element, and the styles can be applied in a number of different ways.CSS allows for much richer document appearances than HTML ever allowed, even at the height of its presentational fervor. CSS lets you set colors on text and in the background of any element; permits the creation of borders around any element, as well as the increase or decrease of the space around them; lets you change the way text is capitalized, decorated (e.g., underlining), spaced, and even whether it is displayed at all; and allows you to accomplish many other effects.