What is the difference between class and id in css?

Question

About css

Answer 1

Id is unique and can be used on only one element.

Class can be used on more html elements.
You use class when you want to make more things that look the same, or have the same styles.

Answer 2

ID's are unique
Each element can have only one ID
Each page can have only one element with that ID

Classes are not unique
You can use the same class on multiple elements.
You can use multiple classes on the same element.