AI reasoning is the model having a conversation with itself before it answers you. It works the task through in an internal dialogue, plans an approach, checks its own working, and only then writes the reply you actually see.
What AI reasoning actually is
Ask someone their name and they answer instantly. No thinking required. Ask them something complicated and the instant answer is a poor one, because nobody worked anything out first.
Models split the same way. A standard model returns an answer the moment you press enter, and on hard questions the quality is lower for it. A reasoning model takes its time.
Reasoning down to its fundamental first principles is just a conversation with yourself on the task at hand.
Luka Eric, 0:38
Take 23 × 47. The model has not memorised that. So it pulls the sum apart, rewrites it as 23 × 50 minus the remainder, and works through it in steps. Then it goes back over its own working and asks whether that was the right way to do it. Verification is a large part of what a reasoning model spends its time on.
That internal dialogue is the whole mechanism. Everything else about reasoning models follows from it.
What reasoning costs you
A standard model might answer a simple question in 200 tokens. Put the same question to a reasoning model and it can spend 3,000 tokens on the reasoning alone, looping and testing itself before it commits to anything. Same architecture, same input, somewhat better output, roughly 15 times the tokens.
Time moves with the tokens. Ask Claude or ChatGPT something and sometimes it reasons for two seconds, sometimes for 30 or 40.
Standard model or reasoning model?
| Standard model | Reasoning model | |
|---|---|---|
| Speed | Answers within a few seconds | Can run to a couple of minutes |
| Cost | Baseline | Around 15x the tokens |
| Easy task | The right choice | Overkill |
| Hard task done carefully | Quality drops | The reason to use one |
Reasoning earns its cost on four kinds of work: hard mathematical questions, complex code, multi-step planning, and anything dynamic enough that you want the model to be careful with it.
Standard models cover the rest and cover it well. Drafting a reply to a customer, summarising notes from a site visit, turning an after-hours call into a job description: quick answers, and the quality holds up.
Six months ago you had to make that call yourself, prompt by prompt. It matters less now. The best models have reasoning built in and work out for themselves when a question needs it, whereas the earlier reasoning models reasoned on every single question whether it deserved the thinking or not.
Why orchestration runs on a reasoning model
Orchestration is the distribution of tasks across multiple AI agents. It runs on a strong reasoning model, because the orchestrator has to take a query, break it into fragments, and hand each fragment to another agent or another model to carry out.
Splitting the work correctly is the hard part of that job. Get the split wrong and every agent underneath does its own piece perfectly well on the wrong task. When you build anything with more than one agent in it, the model doing the splitting is the one worth paying for.