Model

One specific, named AI you can pick and pay for. Each one is an LLM (a program trained on an enormous pile of text, which is what lets it write and reason at all); "model" is the word for the particular one you chose.

Like hiring. The trade is the same, the individuals are not — they differ in how sharp they are, how fast they work, and what they charge.

Why it matters: which model you point at a job is one of the biggest cost levers you actually control, and it's a decision rather than a default. Cheap and fast for sorting the inbox. Expensive and careful for reading a contract. Using the clever one for everything is the most common way to overspend on AI.

Related: LLM (large language model) · Model tiers (Haiku / Sonnet / Opus)