Characters
Characters
Lesson Objectives
- Different characters set such as:
- ASCII
- Extended ASCII
- Unicode
- Applications of each of these character sets.
What is a character?
- A character or symbol is present on the keyboard.
- It has a specific character code that consists of numbers.
- A code is generated for each character or symbol while typing on a keyboard.
- This code is then converted to its character or symbol for displaying and printing purposes.
Character sets
- A complete set of all the characters is called a character set.
- Different languages are represented using different character sets.
- These character sets are unique to meet global standards.
ASCII

- The ASCII (American Standard Code for Information Interchange) character set is a 7-bit set of codes that can represent 128 different characters.
- This consists of upper-case letters, lower-case letters, digits, punctuation marks, special characters, and control characters.
- ASCII code is used for English only.
- Below are ASCII examples:

Complete list of ASCII characters

Extended ASCII
- Extended ASCII code consists of an 8-bit character set, and hence 256 different characters can be encoded.
- Characters used in European languages can also be represented in this coding.
Unicode

- Unicode is the industrial standard for encoding characters in most of the world’s writing systems.
- Initially, this was a 16-bit system that permitted over 65 000 characters.
- The number of bits has now been extended up to 32, permitting coding of several billions of characters.
- This system uses 8 to 32 bits per character.
- Because of a higher number of bits per character in Unicode, the files occupy a higher memory space too.
- Facebook and Google also use the Unicode system as users communicate in different languages.
- The ASCII codes for the characters and symbols remained unchanged in Unicode.
- The codes for characters from other languages were added to the list.
- Unicode allocates character codes for languages all over the world.
- Several code pages are used to represent Unicode.
- Microsoft word provides an option for users to select letters from other languages such as Thai, Greek, and Latin.
- A user can also type a specific character in a document.
- For example: to enter the character “฿”, its Unicode (OE3F) is typed, and then ALT+X keys are typed.
Related Worksheets: