What AI actually is, and which one to use

Which AI assistant should you use? If your company already pays for one, use that one. If it doesn't, the honest answer is that ChatGPT, Claude, Gemini and Copilot can all do the vast majority of what most professionals need, so the fastest route is to pick one and start rather than spend a week comparing them.

This guide does two things. It gives you a one-sentence definition of what an AI assistant actually is and how it differs from a search engine, and it gives you a five-line rule that picks your assistant in under a minute. It is Chapter 1 of the AI Bootcamp, a free course of 90 skills across 36 chapters and 3 tracks.

We publish AI systems like this for 300,000+ senior professionals at AI Central, and more of them live in the AI Central Library.

Most AI education is a pile of disconnected tips. A carousel here, a video tutorial there, a cohort course that goes out of date before the refund window closes. None of it is built to be read in order, so nothing compounds. You finish twelve videos and can recite twelve facts, not perform one new skill.

Choosing between the four major assistants has the same problem in miniature. Picking the "best" one is comparison-shopping dressed up as diligence, and it is the single most common reason people delay starting at all.

There is a second, quieter reason people stall. Search engines and AI assistants look like the same thing: a box you type a question into. So people use them interchangeably, get a disappointing result, and blame the tool. Knowing which box you opened changes what you should expect back, and how much you should trust it.

In one sentence: it is a program you talk to in plain language that reads what you write and writes back a reply built specifically for what you asked. Not a search result, not something pre-written, but something generated fresh, every time, for you.

That is the whole idea. Everything else in this course is about getting better at the conversation, not learning some separate technical skill.

It helps to remember the two things it is not. A search engine finds pages other people already wrote. A template gives you words someone chose before they knew your question. An assistant does neither: it composes an answer to the exact thing you typed, at the moment you typed it.

You will see people call this a "chatbot," a "model," a "large language model," or an "LLM." Those words all point at the same thing you are about to open in a browser tab. This course says assistant. If you want the ground-floor version of this material, our beginner's guide to generative AI covers the same territory from scratch.

A search engine is a directory. It finds pages other people already wrote, ranks them by relevance, and hands you a list of links. Its cost is that you still have to open the pages and piece it together yourself. It is fast and checkable when the answer already exists, written down, on some page: a store's opening hours, a definition, a specific person's title.

An AI assistant is a collaborator. It reads the exact words you typed and writes a brand-new answer built for that question, one that did not exist a second earlier. It is strongest exactly where search is weakest: when the answer doesn't exist anywhere as a single page, because it needs combining, summarising, drafting or explaining in your specific context.

Its cost is that it can sound just as confident when it is wrong as when it is right. Chapter 8 of this course is entirely about catching that.

Neither tool retires the other. You will keep searching for facts you can verify on sight. You are here to add a second tool for the much larger category of work that search was never built to do.

ChatGPT, Claude, Gemini and Copilot. Four assistants doing the same job, and what actually tells them apart is one line each.

The one most people have heard of, and still the most widely used, though the gap is narrowing as Claude, Gemini and Copilot grow. It also has the most available help if you get stuck, simply because more people use it.

Known for being especially careful and thorough with longer, more complex tasks: writing, analysis, following detailed instructions closely. If that is your work, our guide on how to stop prompting Claude the basic way is the natural next step once you have an account.

Built into Google's other products, from Search and Gmail to Docs, Sheets and Slides. If your work already lives there, Gemini reaches into it most naturally.

Lives directly inside Word, Excel, Outlook and Teams. If your company already runs on Microsoft 365, Copilot reaches into the apps you are already sitting in, without a separate tab.

Here is the thing worth saying plainly: for the next 89 lessons, the differences between these four matter far less than actually starting. All four can do the vast majority of what this course teaches.

Use this rule instead of a comparison table. Read from the top and stop at the first line that is true for you.

Pick that one. The licence is already bought and the security review is already done. Stop here.

Pick Copilot. It sits inside the Word, Excel, Outlook and Teams you already have open.

Pick Gemini. It reaches into Gmail, Docs, Sheets and Slides without you moving anything.

Pick Claude. Long, careful work is what it is known for.

Pick ChatGPT. It has the most available help if you get stuck, simply because more people use it. This last line catches everyone else, and it is the right answer far more often than people expect.

Whichever you choose, you can switch later. Nothing here locks you in. The accounts are free to open and the conversations are yours. If you want the mechanics of getting set up on any of them, we walk through it in our setup guide for ChatGPT, Claude and Copilot.

Before: you type a question into whichever box happens to be open, out of habit rather than fit, and you blame the tool when the answer disappoints. You have been meaning to "get into AI" for months, and the comparing never ends because there is always one more review to read.

After: you can say in one sentence what an assistant does and how it differs from search, you can name the four that matter and tell them apart, and you have picked yours. That is a decision, not a fact, and it is the one thing the rest of the course assumes you have made.

Two things carry into Chapter 2: the assistant you picked, and one real task from your week. Something you explained to a colleague, wrote from scratch, or looked up. Chapter 2 opens the assistant you chose, creates the account, and shows you the one screen you will return to for the rest of the course.

The rest of the syllabus lives in the AI Central Library, and if you want a set of one-page references to keep beside you while you work, start with our free AI cheat sheets.

An AI assistant is a program you talk to in plain language that reads what you write and writes back a reply built specifically for what you asked. The reply is generated fresh each time rather than retrieved from a page someone else already wrote.

No. A search engine is a directory that finds and ranks pages other people wrote, and returns links. An AI assistant reads your exact question and composes a new answer for it. Search is better when the answer already exists on a page and you want to verify it. An assistant is better when the answer needs combining, summarising, drafting or explaining.

All four can do the vast majority of everyday professional work, so "best" is the wrong question. Use the rule instead: if your company pays for one, use it; if you run on Microsoft 365, use Copilot; if you live in Google's tools, use Gemini; if you will be doing serious writing, use Claude; otherwise use ChatGPT.

Yes. Nothing about picking one locks you in. The accounts are free to open, the conversations are yours, and the skills transfer, because what you are learning is how to have the conversation rather than how to operate one specific product.

Because fluency and accuracy come from the same process. The assistant composes an answer to your question and has no separate signal telling it when it is unsure, so a wrong answer arrives in the same confident tone as a right one. That is why anything that matters needs an outside check, and why a full chapter of this course is dedicated to catching it.