Unicode

Unicode is a character encoding standard designed to support the representation and processing of text from all writing systems. It assigns a unique code point to each character, symbol, punctuation, and control function, enabling consistent encoding, storage, and interchange across software and platforms.

Unicode was developed by the Unicode Consortium and is coordinated with ISO/IEC 10646. It defines a repertoire that includes more than 100,000 characters across multiple scripts, symbols, and emoji. The code space ranges from U+0000 to U+10FFFF, organized into 17 planes, with the Basic Multilingual Plane containing the most commonly used characters.

Encoding forms: UTF-8, UTF-16, and UTF-32. UTF-8 is variable-length and ASCII-compatible, using 1 to 4 bytes per code point. UTF-16 uses 2 bytes for most characters and 4 bytes for supplementary characters via surrogate pairs. UTF-32 uses a fixed 4 bytes per code point. Endianness and byte order marks apply to UTF-16 and UTF-32 as needed.

Within Unicode, characters may be combined with diacritics or other marks, leading to normalization forms such as NFC, NFD, NFKC, and NFKD that define canonical or compatibility equivalence of text. Rendering requires fonts and rendering engines to map code points to glyph shapes.

Impact and usage: Unicode is the dominant standard for text encoding in modern software, the web, and data interchange. It supports internationalization and multilingual text, but practical limits include font coverage and the complexity of emoji selection and variation selectors.