Guys what is the use of borders, margins and paddings in css3

Question

They're used alot and i wanted to know what's their use and how do i use them.thanks

Answer 1

https://i.stack.imgur.com/A6YUp.png

Answer 2

To position elements

Answer 3

I know that but they're used in every lesson and sometimes they can get confusing. especially the margin property. i just want to know how and when to use them. thx in advance for being a wonderful community.