For following recursive function,will recursion work for fib(x-1) first & then on fib(x-2) or will recursion work simultaneously

Question

def fib(x):
if x == 0 or x == 1:
return 1
else:
return fib(x-1) + fib(x-2)
print(fib(4))

Answer 1

since python starts left to right then fib(x-1) works first

Answer 2

Recursion will start from left to right only
So fib(x-1) recurses first
then by fib(x-2)

but I am not clear with this iteration if any one knew help me with it

Answer 3

I still don't follow this code. The output is 5, but how? Tried inserting some print statements but still not clicking for me