character-encoding

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Character sets

A character set is all the characters and symbols that can be represented by a computer system
Each character is given a unique binary code
Character sets are ordered logically, the code for ‘B’ is one more than the code for ‘A’
A character set provides a standard for computers to communicate and send/receive information
Without a character set, one system might interpret 01000001 differently from another
The number of characters that can be represented is determined by the number of bits used by the character set
Two common character sets are:
- American Standard Code for Information Interchange (ASCII)
- Universal Character Encoding (UNICODE)

ASCII is a character set and was an accepted standard for information interchange
ASCII uses 7 bits, providing 2⁷ unique codes (128) or a maximum of 128 characters it can represent
This is enough to represent the letters, numbers, and symbols from a standard keyboard
The sixth bit changes from 1 to 0 when comparing uppercase and lowercase characters
- a 0110 0001
- A 0100 0001
- b 0110 0010
- B 0100 0010
This made conversion between the two much easier
This speeds up the overall usability of the character set

ASCII only represents basic characters needed for English, limiting its use for other languages

Extended ASCII uses an 8th bit, providing 256 unique codes (2⁸ = 256) or a maximum of 256 characters it can represent
This allows for non-English characters and for drawing characters to be included

UNICODE is a character set and was created as a solution to the limitations of ASCII
UNICODE uses a minimum of 16 bits, providing 2¹⁶ unique codes (65,536) or a minimum of 65,536 characters it can represent
UNICODE can represent characters from all the major languages around the world
UNICODE was designed to create a universal standard that covered all languages and all writing systems
The first 128 characters in the UNICODE character set are the same as ASCII

	ASCII	UNICODE
Number of bits	7-bits	16-bits
Number of characters	128 characters	65,536 characters
Uses	Used to represent characters in the English language.	Used to represent characters across the world.
Benefits	It uses a lot less storage space than UNICODE.	It can represent more characters than ASCII. It can support all common characters across the world. It can represent special characters such as emoji’s.
Drawbacks	It can only represent 128 characters. It cannot store special characters such as emoji’s.	It uses a lot more storage space than ASCII.