what is the use of classmethod in python code example

Example 1: python: @classmethod

class Float:
    def __init__(self, amount):
        self.amount = amount

    def __repr__(self):
        return f'<Float {self.amount:.3f}>'

    @classmethod
    def from_sum(cls, value_1, value_2):
        return cls(value_1 + value_2)


class Dollar(Float):
    def __init__(self, amount):
        super().__init__(amount)
        self.symbol = '€'

    def __repr__(self):
        return f'<Euro {self.symbol}{self.amount:.2f}>'


print(Dollar.from_sum(1.34653, 2.49573))

Example 2: python classmethod

class point:
	def __init__(self, x, y):
    	self.x = x
        self.y = y
        
    @classmethod
    def zero(cls):
    	return cls(0, 0)
        
    def print(self):
    	print(f"x: {self.x}, y: {self.y}")
        
p1 = point(1, 2)
p2 = point().zero()
print(p1.print())
print(p2.print())