The != operator checks whether two objects have different values.

The is not operator checks whether two references point to different objects in memory

first = [10, 20]
second = [10, 20]

print(first != second)
print(first is not second)
            

Output:

False
True
            

  The lists have the same values, so first != second is False. However, they are separate objects, so first is not second is True.