Factorial using classes in Python

Can anyone please explain this code :

class Factorial:

def init(self,n): self.n = n

def factorial(self):
    if self.n == 0:
        return 1 
    else:
        temp_n = self.n
        self.n -= 1
        return temp_n * self.factorial()

fact = Factorial(5) print(fact.factorial())