:A very simple definition of a function is like having '''smaller programs inside a larger program''' that can be run by name to perform '''repeated or commonly routine tasks'''. By calling the function by name to run code that is already stored in internal memory prevents the program from repeating the entry of repetitive code, thus reducing the size of the program and making it execute more efficiently. When creating programs that define and use functions, the programming task can be viewed as creating coding blocks (or '''modules'''). This is why creating programs that use functions is referred to as '''modular programming'''.