CSS Classes & ID Selectors

Did you ever wonder about the difference between a CSS class and a CSS ID selector?

A CSS class has a leading dot or period, as in the following example:

.classname

A CSS class can be applied multiple times in a page.

An ID selector has a leading pound sign, as in the following example:

#selectorname

A selector is an identification for one specific item and it can be used only once in a page.