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AI glossary · P1

Inference

Inference is the moment when the model produces an answer from your request.

Technical basics 4 min read Updated 2026-05-22
— Definition

Inference, in plain words

Inference is the moment when the model produces an answer from your request.

Explain inference as the moment the model answers, not the moment it learns.

A concrete example

When I type a question into Claude, that's inference. The training already happened months ago.

Why it matters

You pay in inference every time you use a model. Understanding that cost means steering your AI usage.

It's what you pay for on every API call or every message handled by a hosted model.

Don't mix it up with

Latency: Latency is the total delay you feel between your request and the answer.

Token: A token is a small chunk of text the AI counts to measure what it reads, writes, and bills.

Common mistakes

  • Mixing up training time and inference time.
  • Thinking a model learns from your prompts during inference (untrue for most).
  • Forgetting that inference costs more on reasoning models.

Quick checklist

  • First I check whether the word names a concept, a tool, a risk, or a metric.
  • I tie it to a concrete case: When I type a question into Claude, that's inference. The training already happened months ago.
  • I keep the main trap in mind: Mixing up training time and inference time.

Quick questions

What is Inference in AI?

Inference is the moment when the model produces an answer from your request.

Where will I run into Inference?

It's what you pay for on every API call or every message handled by a hosted model.

Which word should I read next?

Start with Latency, Token, AI model.

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