# Data representation: A Comprehensive Overview (2021)

## Introduction

The computer is incapable of comprehending human language. Any data fed to a computer, such as letters, symbols, images, audio, videos, and so on, should be converted to machine language first. In this article, we will discuss data representation, binary number representation, pictorial representation of data, graph representation in the data structure, and the importance of graphical representation of data.

## 1. What exactly is Braille?

Braille is a touch-reading and writing device for the blind that uses raised dots to represent the alphabet’s letters. It also includes punctuation mark equivalents as well as symbols that denote letter groupings. Braille is read by moving the hand or hands along each line from left to right. Reading is usually performed with both hands, with the index fingers doing the bulk of the job. Reading pace is about 125 words per minute on average. However, higher speeds of up to 200 words per minute can be reached. People who are blind should review and research the written word using the braille alphabet. They will also learn about writing conventions like spelling, punctuation, paragraphing, and footnotes.

## 2. Numbers in data representation

We are taught the idea of numbers from a young age. Anything is a number to a machine, including alphabets, images, sounds, and so on. There are four different types of number systems:

• The binary number scheme has only two possible values: 0 or 1.
• The octal number system is used to represent values with eight digits.
• The decimal number system is used to describe values with ten digits.
• The hexadecimal number system uses 16 digits to represent values.

Bits A bit is the smallest unit of data that a machine can understand or use. Bits are typically found as groups in computers.

A byte is an eight-bit group of information. A nibble is described as half a byte.

• The decimal (Base 10) number system has ten symbols. It’s written in positional notation. The least-significant digit (rightmost digit) is of the order of 10^0 (units or ones).
• Binary is a type of data that can (Base 2) The binary number system has two symbols: 0 and 1, which are referred to as bits. It’s a positional notation as well. A binary number will be denoted by the suffix B. Prefix 0b or 0B (e.g., 0b1001000) or prefix b with the bits quoted (e.g., b’10001111′) are used in some programming languages to represent binary numbers.
• Number System in Hexadecimal (Base 16): The hexadecimal number system employs 16 symbols referred to as hex digits. It’s referred to as a positional notation. A hexadecimal number (abbreviated as hex) will be denoted by the suffix H.

## 3. Text in data representation

Text code is a standard format for representing letters, punctuation marks, and other symbols. The four most common text code systems:

EBCDIC: EBCDIC is an IBM-developed data-encoding scheme that uses a specific eight-bit binary code for each number, alphabetic character, punctuation marks, accented letters, and non-alphabetic characters. EBCDIC differs from ASCII, the most commonly used text encoding scheme, in that it divides each character’s eight bits into two four-bit zones.

ASCII: ASCII stands for American Standard Code for Information Interchange, and it is a standard for allocating letters, numbers, and other characters to the 256 slots available in an 8-bit code. Binary, which is the language of all computers, is used to construct the ASCII decimal (Dec) number. The lowercase “h” character (Char) has a decimal value of 104, which is “01101000” in binary, as seen in the table below. The X3 committee, which is part of the ASA, established and published ASCII for the first time in 1963.

Extended ASCII: To represent text in a computer system, we assign a unique number to each character. This number is referred to as its code. We can then use binary ones and zeros to store this code on the computer. Computers can understand ASCII code because it tells them how to represent text. Each character in ASCII is represented by a binary value (letter, number, symbol, or control character). Extended ASCII is a variant of ASCII that supports 256 different characters. Since extended ASCII uses eight bits to represent a character instead of seven in standard ASCII, this is the case. In extended ASCII, the maximum number of characters that can be expressed is 256.

Unicode: Many of these schemes used code pages with only 256 characters, each of which needed 8 bits of storage. Although this was relatively lightweight, it was insufficient to hold ideographic character sets with thousands of characters, such as Chinese and Japanese. It also prevented the coexistence of character sets from multiple languages. Unicode is an attempt to unify all of the various text-encoding systems into a single universal standard.

## 4. Images and Colours in data representation

Computer screens and similar devices often use three colours, but they need a different set of primary colours since they are additive, meaning they start with a black screen and add colour to it. The colours red, green, and blue (RGB) are used in additive colours on computers. On a computer screen, each pixel comprises three tiny “lights”: one red, one green, and one blue. All of the different colours can be created by varying the amount of light coming from each of these three. You will experiment with RGB in the following interactive.

## 5. Program Instructions in data representation

We can interpret an entire program using binary in the same way as representing text or numbers using it. Since a program is nothing more than a set of instructions, we must first determine how many bits to use to represent each instruction and interpret those bits. Operation and operand are two pieces of machine code that are usually combined in instructions. Entire computer programs can be analysed in the same binary format by using bits to represent both the program instructions and data forms such as text, numbers, and images. This makes it possible to store programs on discs in memory and transfer them over the internet just like files.

## Conclusion

Computers are information-processing devices. You will use them to view, listen to, create, and edit data in documents, photographs, videos, sound, spreadsheets, and databases. They allow you to compute and measure numerical data, as well as send and receive data over networks. The computer must reflect the information in some way within the computer’s memory, as well as store it on disc or send it over a network, for all of this to function.

For counting and calculating, humans use the decimal (base 10) and duodecimal (base 12) number systems (probably because we have ten fingers and two big toes). Since computers are made up of binary digital components (known as transistors) that operate in two states – on and off – they use the binary (base 2) number system.

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