Setting CSS properties to specific values is the core function of the CSS language. The CSS engine calculates which declarations apply to every single element of a page in order to appropriately lay it out and style it. What is important to remember is that both properties and values are case-sensitive in CSS. The property and value in each pair is separated by a colon (:).
There are more than 300 properties that can be used to style HTML.
Another good source with tutorials is W3Schools
This is a great source of TAGS