C i dont get it

Question

Im doing the lessons and have the right answer but i dont understand it

Answer 1

It's called "printf" cause it's full form is print function and it's stored in the header file where u write( #include <stdio.h>) and it's full form is "Standard Input Output File".

Hope this helps : )

Answer 2

Its not that i have a problem with a question i mean i dont understand the whole thing. For example why is it called printf or how do i know when to put „case“ for example im new in c and its hard to understand