Difference between pseudo-class and pseudo-Element

Similarities:

The syntax of the pseudo-class and the pseudo-element are both set to selector or selector. Class.

Differences:

The operation object of the pseudo-class is an existing element in the document tree, while the pseudo-element creates an element other than the document quantity. Therefore, the difference between the pseudo-class and the pseudo-element is: whether an element other than the document tree is created. The pseudo-class has only one colon, and the pseudo-element has two colons.

Difference between pseudo-class and pseudo-Element