# Python - Understanding Functions (for beginners)

Python functions are blocks of code that carry out particular tasks. Functions can accept inputs, often known as arguments, and are defined with the `def` keyword. Code can be reused and encapsulated using them.

To put it in plain language, we say, A function is a section of code that only executes when called. A function can take parameters, or data, as input. Data can be returned by a function.

```python
## Performing Simple Arithmetic Operations with out using Function (a linear code)

Num1 = 60
Num2 = 5

Result1 = Num1 + Num2
print("The sum of numbers is:",Result1)

Result2 = Num1 - Num2
print("The difference of numbers is:",Result2)

Result3 = Num1 * Num2
print("The product of numbers is:",Result3)


### Performing Simple Arithmetic Operations using Function

Num3=80
Num4=8

def addition():
    add = Num3 + Num4
    print("The sum of num3 and num4 is:",add)

def sub():
    diff = Num3 - Num4
    print("The difference of num3 and num4 is:",diff)

def mul():
    product = Num3 * Num4
    print("The product of num3 and num4 is:",product)


addition() ### we need to explicitly invoke/call on the functions in python to get the code inside  the function executed
sub()
mul()

###OUTPUT for the above:
@skmak1111 ➜ /workspaces/python (main) $ python Test_Func.py
The sum of numbers is: 65
The difference of numbers is: 55
The product of numbers is: 300
The sum of num3 and num4 is: 88
The difference of num3 and num4 is: 72
The product of num3 and num4 is: 640
@skmak1111 ➜ /workspaces/python (main) $
```