Main Seletors in CSS

There are lots of selectors in CSS but here are 4 main selectors your might need.

Selector
.class
Example:
.intro
Example with description:
Select all the classes with name ="intro"
Selector
#id
Example:
#firstname
Example with description:
Select all the element id="firstname"
Selector
element
Example: 
p/H
Example with description:
Select all <p>/<H>elements.
Selector
element element
Example:
<div> <p>
Example with description:
Select all <p> inside a <Div>

There are lot more selectors, Will add those soon