Vocabulary

Understand the term. Connect the concept.

A practical dictionary of 512 AI, machine learning, mathematics, and programming terms from HerbDev’s AI Vocabulary app. Start with a definition, explore an example, then follow the concepts behind it.

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Token

Natural Language Processing · Level 1 of 5

Token

A discrete unit in a model's input or output sequence.

A token is not necessarily a whole word.

Example

One English word is represented by two subword units.

Listen to the definition and example

Audio transcript

Token. A discrete unit in a model's input or output sequence. A token is not necessarily a whole word. For example: One English word is represented by two subword units.

Explore this concept

A useful analogy

A piece from the tokenizer’s set of building blocks.

Why it matters

This helps you understand how language becomes data and where processing can lose meaning.

Technical detail

Text maps to integer IDs drawn from a fixed vocabulary. Token boundaries depend on the tokenizer and may not match word boundaries.

Common misconception

One word is not always one token.

Related concepts

Quick recall question

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Put the terminology into context: How AI works · Machine-native representations · All learning paths

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