We can define/create our CSS styles in a separate file and then link it to the page we want. Styles are normally saved in external .css files.
CSS helps to solve lot of works. For a single page it will be easy to specify the styles. While we are creating more pages it will be very hard to specify the styles in each and every page. In this situation External Styles sheets are used.
Declaration groups are surrounded by curly brackets.
Example:
p
{
color:red;
text-align:center;
}