Data Representation in Computers PDF

Cs What is Data Representation? Data representation is the way we store, organize, and manipulate information in a computer. Computers don't understand text, pictures, or sound in the way humans do. Instead, they use numbers (often in binary form) to represent all kinds of data like text, images,...

Cs What is Data Representation? Data representation is the way we store, organize, and manipulate information in a computer. Computers don't understand text, pictures, or sound in the way humans do. Instead, they use numbers (often in binary form) to represent all kinds of data like text, images, sound, and even videos. 1. Binary System: Computers work with the binary system, which only uses two digits: 0 and 1. These are called bits (short for binary digits). Everything you see and interact with on a computer—whether it's a letter, a picture, or a sound—gets turned into a long series of 0s and 1s (called binary code) that the computer can process. 2. How Do We Represent Different Types of Data? Text: Text is represented using codes like ASCII or Unicode. ○ ASCII: Each letter, number, or symbol is assigned a unique number (e.g., the letter A is represented as the number 65 in ASCII). Computers convert these numbers into binary to store the text. ○ Unicode: This is a more powerful system, capable of representing a huge variety of characters, including special symbols, emojis, and characters from different languages. Example: The word "Hello" in ASCII looks like this in binary: ○ H = 01001000 ○ e = 01100101 ○ l = 01101100 ○ l = 01101100 ○ o = 01101111 So, "Hello" becomes: Copy code 01001000 01100101 01101100 01101100 01101111 Images:  Images are made of pixels, and each pixel has a color. Each color is represented using numbers (usually in RGB format). ○ RGB: Each color is described by a combination of three numbers for Red, Green, and Blue (each ranging from 0 to 255). For example: Red = (255, 0, 0) Green = (0, 255, 0) Blue = (0, 0, 255) Computers convert these numbers into binary to store and display the image. Sound: Sound is represented as a series of samples (tiny snapshots) of the sound wave. These samples are converted into numbers, which are then turned into binary for storage. The more samples you take and the higher the quality of each sample, the better the sound quality will be. 3. Why is Binary Important? Binary is easy for computers to understand because at the most basic level, a computer is just a collection of circuits that can either be on or off. These on/off states are perfect for representing the two binary digits: 0 and 1. When you write a program or work with data, the computer is doing lots of calculations and operations with binary values in the background. 4. How Is Data Stored? Computers store data using different storage devices, like hard drives or solid-state drives (SSDs). Each of these devices stores binary data using tiny electronic switches or magnetic fields. For example: In a hard drive, data is stored as magnetic charges on the disk's surface. In a solid-state drive (SSD), data is stored in flash memory, where the charges are stored in cells. 5. Compression and Encoding: Sometimes, we want to make the data smaller to save space (for example, with images or videos). This is called compression. The computer looks for patterns and uses algorithms to store data in a more compact way. Encoding is a way of transforming data into a different format to make it easier to transmit or store. Key Points to Remember:  Data representation is how we store and organize information in a computer. Everything is turned into binary (0s and 1s) for the computer to understand. Text, images, and sound are all converted into binary numbers using systems like ASCII, RGB, and sound samples.