Describe the different types of functions in Python using appropriate examples.

The different types of functions in Python are as follows :

1. Built-in functions — These are pre-defined functions and are always available for use. For example:

name = input("Enter your name: ")
name_length = len(name)
print("Length of your name:", name_length)

In the above example, print(), len(), input() etc. are built-in functions.

2. User defined functions — These are defined by programmer. For example:

def calculate_area(length, width):
    area = length * width
    return area

length = 5
width = 3
result = calculate_area(length, width)
print("Area of the rectangle:", result)

In the above example, calculate_area is a user defined function.

3. Functions defined in modules — These functions are pre-defined in particular modules and can only be used when corresponding module is imported. For example:

import math
num = 16
square_root = math.sqrt(num)
print("Square root of", num, ":", square_root)

In the above example, sqrt is a function defined in math module.