Unicode and ASCII are both character encoding standards, while UTF-8 (Unicode Transformation Format-8) is a specific implementation of Unicode. Here are the main differences between the three:
Character set: ASCII is a 7-bit encoding scheme that can represent 128 characters, while Unicode is a much larger character set that can represent almost all the characters used in any language. UTF-8 is a way of encoding Unicode characters in a specific format that allows for efficient storage and transmission.
Encoding scheme: ASCII uses a fixed-length encoding scheme, where each character is represented using 7 bits (or one byte) of data. Unicode uses a variable-length encoding scheme, where characters can be represented using 1 to 4 bytes of data, depending on the character's Unicode value. UTF-8 is also a variable-length encoding scheme, but it uses a specific algorithm to encode Unicode characters in a way that is backward-compatible with ASCII.
Multilingual support: ASCII is primarily used for representing characters in the English language, while Unicode is designed to support characters from all languages, scripts, and symbols used around the world. UTF-8 is a specific implementation of Unicode that can represent all of the characters in the Unicode standard, while still being backward-compatible with ASCII.
In summary, while ASCII is a simple and widely-used encoding scheme for representing English text, Unicode is a more complex and comprehensive encoding scheme that supports almost all languages and scripts in the world. UTF-8 is a specific implementation of Unicode that provides efficient storage and transmission of Unicode characters, while still being compatible with ASCII.