What is difference between raw_input() and input() functions in Python?

The function raw_input() presents a prompt to the user (the optional arg of raw_input([arg])), gets input from the user and returns the data input by the user in a string. For example,

name = raw_input("What isyour name? ")
print "Hello, %s." %name

This differs from input() in that the latter tries to interpret the input given by the user; it is usually best to avoid input() and to stick with raw_input() and custom parsing/conversion code. In Python 3, raw_input() was renamed to input() and can be directly used. For example,

name = input("What is your name? ")
print("Hello, %s." %name)