Input problem

[Prasoon]

I am new to python....and using python 2.6
I want to know when to use raw_input( ) and when to use input( )???

According to my interpretation one should use input( ) when entering
numbers etc and
raw_input( ) when a string is too be entered.....

Correct me if I am wrong....

Also if I want to enter two numbers 'a' and b such that while entering
them through the keyboard
there is a space between the two...

For example:
>>>Enter two numbers:
 .....12 15

Can I use input( ) such that 12 gets accepted in 'a' and 15 in 'b'????

I mean how to handle spaces???/