I believe I finally understand return. Therefore, I understand this much:

def square_point(x_value, y_value):

x_2 = x_value * x_value

y_2 = y_value * y_value

return x_2, y_2

but I do not understand to arrive here:

x_squared, y_squared = square_point(1, 3)

print(x_squared)

print(y_squared)

mostly:

x_squared, y_squared Where does this come from?