Can anyone explain?

Question

https://code.sololearn.com/cWDhm7gU0oSJ/?ref=app

Answer 1

Recursion

Answer 2

fact(3) first call with 3
3 + fact(3-1) second call with 2
3 + 2 + fact(2-1) third call with 1
3 + 2 + 2 + fact(1-1) in the function as the x==1 it will return 2
3 + 2 + 2
7