In AI, tokens are used to:

1. Break down text into smaller parts: Tokens help to split text into individual words, phrases, or characters, making it easier to analyze and process.
2. Represent language: Tokens can be used to create a vocabulary of unique symbols, each representing a specific word, phrase, or concept. This vocabulary is then used to build more complex representations of language.
3. Build language models: Tokens are used to train language models, such as recurrent neural networks (RNNs) and transformers, which learn to predict the next token in a sequence based on the context.
4. Generate text: Tokens can be used to generate text, such as chatbots, language translation, and text summarization.
5. Classify and analyze text: Tokens can be used to classify text, such as sentiment analysis, spam detection, and topic modeling.