So what exactly does enumerate do?

enumerate() is one of the built-in Python functions. It returns an enumerate object. In our case that object is a list of tuples (immutable lists), each containing a pair of count/index and value. Look at http://docs.python.org/library/functions.html?highlight=enumerate#enumerate

Try the following in the python labs (here we use another built-in function list([iterable]) which returns a list whose items are the same and in the same order as iterable‘s items).

>>> choices = ['pizza', 'pasta', 'salad', 'nachos']
>>> list(enumerate(choices))
=> [(0, 'pizza'), (1, 'pasta'), (2, 'salad'), (3, 'nachos')]

So, in the for index, item in enumerate(choices): expression index, item is the pair of count, value of each tuple: (0, 'pizza'), (1, 'pasta'), ...

We may easily change the start count/index with help of enumerate(sequence, start=0)

for index, item in enumerate(choices, start = 1):
    print index, item

or simply with a number as the second parameter

for index, item in enumerate(choices, 1):
    print index, item

in opposite to the lesson’s hint

for index, item in enumerate(choices):
    print index + 1, item