A Large Language Model (LLM) is an AI system trained on massive amounts of text to predict the next token in a sequence. The prediction capability scales into broader abilities (reasoning, code generation, analysis, conversation, translation, summarization) as models grow in size and training data. Modern frontier LLMs range from 70 billion to 1+ trillion parameters and are the technology underlying ChatGPT, Claude, Gemini, Llama, and other generative AI products that have transformed software since 2022. It's the specific type of foundation model that handles text.
What LLMs actually do (the mechanics):
Tokens, not words: LLMs break text into tokens (sub-word units). "Tokenization" of a sentence might produce 10-...