A working reference for the vocabulary of modern AI — organized by conceptual layer, not alphabetically. Each definition is written for practitioners and informed generalists: precise enough to cite, plain enough to share. Foundation Layer Large Language Model (LLM) A neural network trained on vast quantities of text to predict and generate language. LLMs learn statistical patterns across billions of documents, enabling them to answer questions, write code, summarize text, and engage in dialogue.

Prompt engineering starts off sounding like a workaround—just phrasing things better so an AI gives a better answer—but it quickly reveals itself as something closer to a new kind of interface design. You’re not writing code in the traditional sense, but you’re also not just “asking a question.” You’re shaping context, defining boundaries, nudging the model toward a particular way of thinking. The input becomes a kind of lightweight program, written in natural language, where structure matters more than people initially expect.