Explore how computer systems store, manipulate, and convert various data types like text, images, and videos through integrated software and hardware. Gain insights into accessible data representation.

Computer systems do not understand human instructions, nor can they perceive real-life data in its raw form. Therefore, computer systems require a way to store and represent information in an accessible way. They use software and hardware components combined to help retrieve information, store it, manipulate it, and convert it back to a human-accessible format. If you want to learn how computer systems perform complex tasks such as storing and manipulating textual data, videos, music, images of your cat, and much more, this course is meant for you.

Information Representation in Computer Systems

A **function** is a code block that takes in an input value or an *argument* and performs an action on it. Figure 1 shows a function that takes an argument, increments it by one, and returns it. In Python, there are two types of functions:

* **Built-in functions** are already defined in Python libraries, and we can call them directly.  

The most common built-in function is the `print` function. It displays the input value on the console.

* **User-defined functions** are functions that we define ourselves in our program and then call them wherever we want.

The user defined function called `increment` is shown in the code snippet below. This function takes one argument, increments it by one and returns the resultant value.



def increment(n):
    return n+1

result = increment(5)
print(result)

You can add two numbers and use the `print` function to visualize the output. 

Likewise, you can use the four basic operators:
* add (+)
* subtract (-)
* multiply (*)
* divide (/)

 and use the `print` function to visualize the output. 
> The order of operations is according to #key# PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction #key#.

## Coding challenge 1
The code snippet below shows a user-defined function, in Python, called `addParenthesis`. Insert parentheses in the highlighted expression below to print 6.5 instead of 14 and click on Test to verify your result.

This lesson will give you an overview of Python. 

Computer basics

Hardware and Software Components of a Computer

Data Representation in Python

Image, Audio, and Video Representation in Python

Data Compression

Overview of Python

Functions

Basic arithmetic operators