If id is unique and can't be used more than once in a document why do we use it, why not just use class???

Answer 1

Because there are singular elements you want to style only once, plus it is useful when you want to locate a certain p or div tag when you are using Javascript

Answer 2

You may want to style a single section @Eyob

Answer 3

@Sami we can use class to style a single section!