How does a computer system represent characters?

A computer system represents characters using standardised numerical codes, such as ASCII or Unicode.

In a computer system, characters are represented as binary data. Each character, whether it's a letter, number, punctuation mark, or special symbol, is assigned a unique binary code. This code is used to store, process, and display the character in the computer system. The most common coding systems used today are ASCII (American Standard Code for Information Interchange) and Unicode.

ASCII is a 7-bit character code where every single bit represents a unique character. It was initially developed in the 1960s for telecommunication systems but was quickly adopted by computers. ASCII can represent 128 different characters (from 0 to 127), including English letters, numbers, punctuation marks, and control characters (like carriage return and line feed). However, ASCII is limited and cannot represent characters from non-English languages.

To overcome the limitations of ASCII, Unicode was developed. Unicode is a universal character encoding standard that includes virtually every character and symbol from all writing systems around the world. It uses a wider range of numbers (up to 21 bits), allowing it to represent over a million unique characters. Unicode is backwards compatible with ASCII, meaning that the first 128 Unicode characters are identical to those in ASCII.

In both ASCII and Unicode, each character is represented by a unique number, known as its code point. For example, in ASCII, the capital letter 'A' is represented by the number 65, while in Unicode, the Greek letter 'α' is represented by the number 945. These numbers are then converted into binary code, which the computer can process.

In summary, a computer system represents characters using numerical codes, with each character assigned a unique binary code. These codes are standardised across different systems, ensuring that the same character is always represented by the same code, regardless of the specific computer or software being used.