Nepedia
Back to Discover
Advanced Reader
💻

Unicode

technology Maturity 11-13 war conflict Next article →

This article covers sensitive topics: war_conflict. Parents can manage visibility in Parental Controls.

Unicode is a universal character encoding standard used to digitize text from all the world's writing systems.

Unicode sample
Unicode sample

It acts as a common language for computers to represent letters, numbers, and symbols. Before Unicode, different computers used many incompatible character sets. These sets often only worked for specific regions or specific computer architectures. If you sent text from one system to another, it often appeared as unreadable garbage characters. Unicode solved this by merging these various sets into one single, massive repertoire. Today, it is used for the vast majority of text on the Internet. It is a critical consideration for any modern software development.

At its most abstract level, Unicode works by assigning a unique number to every character. This unique number is known as a code point. The standard focuses on encoding the underlying characters, which are called graphemes. It does not focus on the specific visual style of a character, such as its size or shape. Instead, the software used to view the text, like a web browser, decides how to render those styles. To store and process these code points, computers use a method called encoding. Encoding translates the abstract code points into sequences of binary data, which are bits and bytes.

Cyrillic cursive
Cyrillic cursive

The standard defines three main encodings: UTF-8, UTF-16, and UTF-32. UTF-8 is the most widely used encoding by a very large margin. This is partly because it is backwards-compatible with the older ASCII standard.

Unicode is a massive and expanding system. Version 17.0 defines 159,801 characters and 172 different scripts. These scripts include various alphabets, abugidas, and syllabaries used in ordinary, literary, and technical contexts. The entire Unicode codespace is capable of encoding more than 1.1 million characters. This vast capacity allows the standard to include many historic scripts, such as Egyptian hieroglyphs.

Hiero O4
Hiero O4

Beyond letters, Unicode also encodes 3,790 emoji. The widespread adoption of Unicode was a major reason emoji became popular outside of Japan. The Unicode repertoire is also kept synchronized with ISO/IEC 10646. These two standards are code-for-code identical with one another.

The history of Unicode began in the 1980s. A group of individuals with ties to Xerox's Character Code Standard began investigating a universal set. In 1987, Xerox employee Joe Becker started this work with Apple employees Lee Collins and Mark Davis. In August 1988, Becker published a draft proposal called "Unicode 88." He chose the name to suggest a unique, unified, and universal encoding. His original design used 16-bit characters to cover the world's living languages. He believed 16 bits would be enough to cover all modern-use characters. By 1991, the Unicode Consortium was incorporated in California. The first volume of the standard was published in October of that year.

As technology advanced, the system had to grow. In 1996, Unicode 2.0 implemented a surrogate character mechanism. This meant Unicode was no longer restricted to just 16 bits. This change increased the available space to over a million code points. This expansion allowed for the inclusion of thousands of rare or obsolete characters. It also allowed for the inclusion of complex characters used in names within CJK languages. To help with the transition from older systems, the first 256 code points mirror the ISO/IEC 8859-1 standard. This makes it easier to convert Western European text into Unicode without losing information.

The Unicode Consortium is a non-profit organization that coordinates all development. Its full members include major computer companies like Adobe, Apple, Google, IBM, Meta, Microsoft, Netflix, and SAP. The Consortium aims to replace all other encoding schemes with Unicode and its UTF schemes. They also manage the process for adding new scripts to the standard. Some scripts, like Jurchen, are currently on the Unicode Roadmap as candidates for encoding. Others, like the Rongorongo script, are waiting for user communities to provide proposals. Organizations like the Script Encoding Initiative also help fund the research needed for these additions.

Unicode provides much more than just a list of numbers. The standard includes detailed charts, reference data, and annexes for developers. These annexes explain complex concepts like character normalization and composition. They also cover character decomposition, collation, and directionality. This guidance is essential for programmers who need to implement text correctly. Even small details, like how to handle different accent marks, are documented.

I acute - soft dotted and Lithuanian dot
I acute - soft dotted and Lithuanian dot

By providing these rules, Unicode ensures that text remains consistent across every platform in the world.

746 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (4)
File:Unicode sample.svg
Unicode sample.svg
File:Hiero O4.png
Hiero O4.png
File:Cyrillic cursive.svg
Cyrillic cursive.svg
File:I acute - soft dotted and Lithuanian dot.svg
I acute - soft dotted and Lithuanian dot.svg
More to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.