General over view
Cascading Style sheets were introduced in late 1996.
Style sheet is a collection of formating styles that can be appliedto a web page.
Generally, allstyles"cascade" into a new style sheet by the following rules in which the number 4 has the highest priority:
2.External style sheet
3.Internal style sheet(inside the tag)
4.Inline style sheet(inside HTML element)
Benefits of Style Sheet
1.Override the browser
Each browser has its own way of displaying web pages.
In past,developers could not control how to display the page in a browser.But style Sheet can be used to override the browser