Definition
A Large Language Model (LLM) is a deep learning model trained on massive amounts of text data that can understand and generate human language. LLMs like GPT-4, Claude, Gemini, and Llama form the "brain" of AI agents, providing the reasoning, language understanding, and decision-making capabilities that agents rely on.
Example
When you ask an AI agent to summarize a 50-page contract, the LLM reads the text, understands the legal concepts, identifies the key terms, and generates a concise summary in plain language.
Why it matters
LLMs are the engine that makes AI agents possible. Understanding their capabilities and limitations is essential for building effective agent workflows.