When the value passed to the index operator is greater than the actual size of the tuple or list, Index Out of Range error is thrown by Python.
>>> a = [1,2,3,4]
>>> a[3]
4
>>> a[4]
Traceback (most recent call last):
a[4]
IndexError: list index out of range
>>> b = (1,2,3,4)
>>> b[4]
Traceback (most recent call last):
b[4]
IndexError: tuple index out of range