Need help in understanding detailed difference between two python codes, both written to find the largest number among three inputs

Please let me help to understand detailed difference between below two codes written to find the largest number among three numbers.

Code1:

def max_num(num1, num2, num3):
    if num1 >= num2 and num1 >= num3:
        return num1
    elif num2 >= num1 and num2 >= num3
        return num2
    else:
        return num3

Code2:

def max_num(num1, num2, num3):
    if num1 > num2 and num1 > num3:
        return num1
    elif num2 > num1 and num2 > num3
        return num2
    else:
        return num3