Please how is psuedo classes and element used and what does * mean in css....

Question

How is the * used and how is the after and before psuedo classes used....

Answer 1

https://www.sololearn.com/learn/CSS/2257/
https://www.sololearn.com/learn/CSS/2258/
Study from the course

And * selects all html elements

Answer 2

But how is it (*) used