n. / Models and tokens
Large language model (LLM)
Definition
A large language model is a neural network trained on very large amounts of text to predict the next token, which lets it write, summarize, translate, reason about text and call tools. Most AI agents use an LLM as the part that decides what to do next.
In more detail
An LLM takes tokens in and produces tokens out, one at a time. It has no memory between calls beyond what you put in the prompt, and its output can vary from call to call. These properties are why LLM applications need tracing: you have to see the exact input a model received to understand its output.
Example
A support agent sends the customer's message and a list of available tools to an LLM. The model answers with a request to call the "lookup_order" tool.
Related terms
