token

A token is a unit that stands for or represents something else. It functions as a sign, marker, or object that confers access, value, or identity within a system or context.

In linguistics and text processing, a token is an instance of a sequence of characters that forms a unit of text, such as a word or punctuation mark. Tokenization is the process of splitting text into tokens; “type” refers to a distinct word form.

In computing, a token is a digital credential used for authentication or authorization. Examples include session tokens, API tokens, and hardware or security tokens. Tokens may be time-limited, cryptographically signed, or presented to prove identity or grant access; JSON Web Tokens are common in web services.

In finance and blockchain, a token is a digital asset on a blockchain. Tokens can be fungible, meaning interchangeable, or non-fungible, representing unique items. They can symbolize currency, securities, governance rights, or physical assets, and may be created through tokenization of real-world assets or as standalone tokens.

The term has a long history as a general term for a sign or symbol that stands in for something else; in modern technology, it has specialized meanings across fields such as security, linguistics, and digital finance.