What Is Generative AI, Really?

Generative AI writes answers instead of finding them. Learn what that means, why a reasoning engine is not a search engine, and why fluent is not the same as correct.


What you'll learn

  • Explain generative AI in one plain sentence
  • Tell a retrieval question apart from a reasoning question
  • Explain why a fluent answer still needs checking
On this page

Ask a search engine "what were our Q3 support trends" and you get links to open and read. Put the same question to Copilot and it writes a paragraph that didn't exist before you asked. One finds existing material. The other generates a response, which makes the wording of your request part of the work.

Generative AI writes answers

Generative AI creates content (text, tables, summaries, images) from an instruction called a prompt. That's the useful definition. Earlier AI systems were commonly used to sort things, such as routing a support ticket or flagging an unusual transaction. Generative AI produces a draft email, a five-row comparison, or a rewritten paragraph.

Three words get used as if they mean the same thing. They don't:

Term What it means Everyday example
Artificial intelligence (AI) The broad field of systems that do tasks we associate with intelligence Routing a support request
Machine learning AI that learns patterns from examples instead of hand-written rules Learning which team a ticket belongs to
Generative AI AI that creates new content from a prompt Drafting the reply to that ticket

Every one of these tasks follows the same arc. You give an input (your prompt and any material you supply), the model processes it, and an output comes back that you can use, edit, or reject. The systems behind Microsoft Copilot are large language models (LLMs): models that learned patterns from an enormous amount of text and use them to generate language. You do not need to know how one works inside to use it well. You need to know what it is good at, and where it slips.

Is Copilot a search engine or a reasoning engine?

Two very different jobs hide inside the words "answer this question," and telling them apart changes how you ask:

  • Retrieval locates information that already exists somewhere. "What is the current mileage reimbursement rate?" You need an authoritative, up-to-date source.
  • Reasoning connects facts, constraints, and priorities into a conclusion. "Given these three venue quotes, which one fits our budget and date?" You need the answer worked out from the supplied facts.

A search engine is built for retrieval. A reasoning engine is built for analysis. Copilot can do both, but it does them best when you know which one you're asking for. "Find the current policy and recommend an option" combines both jobs: retrieve the policy first, then reason over it.

Microsoft Copilot offers conversation modes that lean toward one job or the other. Search is grounded in the web and returns citations you can open, so use it when the answer depends on current public information. Think Deeper uses reasoning models, which suits tasks where you have supplied the facts and need them compared, sequenced, or explained. Neither mode guarantees a correct answer. Each changes how Copilot approaches the request, which is why identifying the job matters more than clever phrasing.

Name the job before you type

Before you send a prompt, ask yourself one question: am I looking something up, or working something out? Retrieval wants a source and a citation. Reasoning wants the facts laid out and the logic shown. Getting this right the first time saves you three follow-ups.

A retrieval question, done right· copilot-chat
Bad example

Find Microsoft tips for writing Copilot prompts.

Good example

Using current, official sources only, find Microsoft's published guidance on writing effective Copilot prompts. Give me the page title, a one-sentence summary, and the link for each source. If you can't find an official page for a claim, say so instead of guessing.

Why this works: A short list of real, openable links to official pages, with "not found" stated where evidence is missing instead of an invented URL.

A reasoning question, done right· copilot-chat
Bad example

Compare these three vendor quotes and tell me which one is best.

Good example

Here are three vendor quotes: [paste quotes with price, delivery date, and warranty]. Using only these details, compare them for a purchase that must arrive before the 30th and stay under $5,000. Show the check for each quote, label anything you assume, and recommend one.

Why this works: A quote-by-quote comparison with the math shown, assumptions flagged separately, and one clear recommendation you can sanity-check yourself.

A fluent answer can still be wrong

An LLM can write smoothly while getting a name, date, or number wrong. The incorrect answer arrives in the same assured voice as the correct one, so tone gives you no warning.

A made-up detail is called a fabrication (you'll also hear "hallucination"). It could be a meeting date missing from your notes, a statistic rounded incorrectly, or a next step the source only implied. These details are easy to miss because they fit the paragraph. The useful question is "where exactly is this supported?" If you can't point to the evidence, the claim still needs checking.

Two assumptions are best dropped early. A bigger or newer model isn't automatically more accurate. Capacity affects how much text a model can consider at once, while accuracy still depends on the source, the task, and your checks. The same prompt can also return different answers on separate runs. Repetition doesn't prove a claim. Check each answer on its own evidence.

The confident wrong answer

A polished paragraph with one invented number in the middle does more damage than an obviously broken answer. Treat every date, figure, name, and commitment as a claim to check against your source before you forward, decide, or act on it.

Facts, guesses, and the line between them

When Copilot writes an answer, it mixes four different kinds of statement, and telling them apart is a skill you'll use forever:

  • A fact is something your source directly supplies: "The venue holds 120 people." It's written down.
  • An inference is a conclusion Copilot worked out from facts: "So it's too small for our 150 guests." Sound, but it's a calculation, not a quote.
  • An assumption is something treated as true without confirmation: "The room will be free that evening." Nobody checked.
  • A recommendation is a proposed action built on all of the above. "Book the larger hall instead."

Copilot rarely labels these for you. It blends them into one smooth paragraph, so ask of each important sentence: which kind is this? Trace a fact to its source, rerun an inference, flag an assumption, and take responsibility for a recommendation. This is the verification skill you'll build through the rest of the module.

Where generative AI is most useful

Keep it on work you can judge. Most useful tasks in this course fall into four groups:

  • Create: produce a first draft, outline, agenda, or list of ideas from scratch.
  • Summarize: compress a long document, thread, or meeting into decisions, risks, and next steps.
  • Transform: shorten text, change its tone, or put the same material into a table.
  • Analyze: compare options or apply a stated rule to information you've supplied.

In each case, you can check the result against something concrete: the source document, the numbers you pasted, or your judgment of the tone. Generative AI is less dependable when verification is difficult, including obscure facts, current prices, and information that changed last week. A quick first draft can still be valuable when checking it takes less time than starting from a blank page. In the next lesson, you'll try these four patterns in Microsoft Copilot and see how its conversation modes affect the result.

Turn Copilot into your tutor· copilot-chat
Bad example

Explain retrieval and reasoning questions.

Good example

Teach me the difference between a retrieval question and a reasoning question. Use one example from my job in marketing operations, explain it in plain language, then ask me one short question to check I've got it.

Why this works: A tailored, one-example explanation followed by a check-for-understanding question, with Copilot acting as a patient tutor rather than an answer vending machine.

Try it yourself

Sort your own questions

The retrieval-versus-reasoning instinct is best built on your real work, not a textbook example. This takes about five minutes.

  1. 01

    Write down three questions you'd genuinely want to ask Copilot this week, from any part of your job.

  2. 02

    Label each one retrieval, reasoning, or both. Underline the word that gave it away: current, official, or price points to retrieval. Compare, plan, or why points to reasoning.

    Hint: If a question needs today's facts and a judgment, it's "both," so retrieve first, then reason second.

  3. 03

    Take the clearest retrieval question and run it in Search. Take the clearest reasoning question and run it in a reasoning mode like Think Deeper.

  4. 04

    Note which answer came with citations and which came as worked-out logic. That contrast is the lesson.

A short list of your own questions, correctly sorted, plus a felt sense of how differently Copilot behaves when it's finding versus working out.

Key takeaways

  • Generative AI creates content from a prompt. It writes an answer instead of finding one.
  • Retrieval looks information up. Reasoning works it out, so name the job before you ask.
  • Fluency is not accuracy. A wrong answer sounds exactly as confident as a right one.
  • A bigger model doesn't guarantee a more accurate answer, and neither does a repeated prompt.
  • Copilot is strongest on create, summarize, transform, and analyze tasks you can check.

Check your understanding

  1. 1. What is the clearest one-sentence definition of generative AI?

  2. 2. You need to know your company's current travel-reimbursement rate before approving an expense. Is this mainly a retrieval or a reasoning task?

  3. 3. A Copilot answer reads smoothly and professionally. What does that prove?

  4. 4. A colleague says a model with a bigger context window will always give more accurate answers. Are they right?

  5. 5. Which task is generative AI best suited to, because you can easily check the result?

Frequently asked questions

Terms used in this lesson

generative AI
AI that creates new content (text, tables, summaries, images) in response to a prompt, rather than finding or sorting existing information.
large language model (LLM)
The kind of model behind Copilot's text features. It generates language from patterns learned across a large amount of text.
retrieval
Locating information that already exists in an authoritative source, the job a search engine is built for.
reasoning
Connecting supplied facts, constraints, and priorities into a conclusion: comparing, planning, or explaining rather than looking up.
fabrication
A plausible-sounding claim an AI produces that isn't supported by the available information, also called a hallucination.

Further reading