Pseudo Elements

::after

The ::after selector inserts something after the content of each selected element.

::before

It is inline by default.

Content

The ::before pseudo-element inserts content before the content of an element.

First Letter

The ::first-letter selector is used to add a style to the first letter of the specified selector.

First Line

The ::first-line selector is used to add a style to the first line of the specified selector.
The ::first-line selector can only be used with block-level elements.

Selection

The ::selection selector matches the portion of an element that is selected by a user.

Challenge

I used multiple pseudo elements:

Assesment

I added the selection pseudo element throughout the entire page. I did this by using putting ::selection in the style sheet and adding styles to change the background and text colors.