Everyone talks about AI, at work, on the news, at family dinners. Far fewer people can explain what it is. This guide covers the basics without jargon: what an AI is, how it produces its answers, what sets ChatGPT, Claude and Claude Code apart, and the precautions to take. Pricing and product descriptions come from Anthropic's official pages and public sources, checked on October 18, 2026, with links at the end.
What is artificial intelligence, in one minute?
France's data protection authority, the CNIL, defines artificial intelligence as a logical, automated process, usually based on an algorithm, that can carry out well-defined tasks. Put simply: a classic program follows rules a human wrote one by one. A modern AI learned its rules on its own, by studying huge amounts of examples.
A concrete example. To recognize a cat in a photo, nobody writes "two pointy ears, whiskers, a tail". You show the program millions of photos, with and without cats, and it works out by itself what makes a cat.
| Term | What it means |
|---|---|
| AI (artificial intelligence) | The whole family: programs that perform tasks we associate with human intelligence |
| Generative AI | AI that produces new content: text, images, audio, code |
| Language model | The "brain" of a text-generating AI, trained on very large amounts of text |
| Assistant (or chatbot) | The app where you chat with that model: ChatGPT, Claude |
| Agent | An AI that does more than answer: it acts (opens a file, sends a message, runs a command) |
How do ChatGPT and Claude produce their answers?
The assistants everyone talks about run on a language model. During training, that model read more text than any human could read in a thousand lifetimes. From it, it learned a skill that sounds simple on paper: guessing the next word.
"The cat is sleeping on the…" The most likely next words: "couch", "bed", "windowsill". The model picks one, then does it again with the next word, and so on.
Repeated thousands of times, with a lot of nuance, this mechanism is enough to write an email, summarize a document, translate, explain an idea or suggest code. It is a simplification, but it explains two important things:
- Why it sounds so fluent: the model has seen so much text that it knows how a sentence should sound.
- Why it can be wrong: it produces the most plausible continuation, not necessarily the true one. More on that below.
What is ChatGPT?
ChatGPT is the AI assistant made by the American company OpenAI. You type a question or a request in a chat window, and it answers. It is the best known to the general public: for many people, "ChatGPT" has become a synonym for "AI".
That is a shortcut, though. ChatGPT is not AI, it is one AI, the same way one soda brand is not "drinks". Other companies offer their own assistants: Claude from Anthropic, Gemini from Google, Le Chat from the French company Mistral AI.
What is Claude?
Claude is the AI assistant made by Anthropic, an American company that describes itself as "an AI safety and research company". Anthropic announced Claude's broader release in March 2023. You use it the same way as ChatGPT: on claude.ai, in a mobile app or on desktop.
In principle, Claude and ChatGPT do the same things: write, summarize, analyze a document, answer questions, help with code. The differences lie in the style of the answers, the features and the pricing. The easiest way to choose: ask both the same question, on a real task from your day, and compare. At Lionea, we mostly use Claude, especially for its Claude Code tool.
What is Claude Code?
Claude Code is an Anthropic tool that takes Claude from talking to doing. The official documentation describes it as a tool that "reads your codebase, edits files, runs commands, and integrates with your development tools". It runs in the terminal (the window where you type commands), in code editors, in the desktop app and in the browser.
The difference from regular Claude is simple:
- With Claude, you type, it answers. You copy its answer and do the work yourself.
- With Claude Code, you describe what you want ("fix this bug", "add a contact page to the site"), and it does it on the computer: it opens the files, writes the code, runs the tests, then shows you what it changed.
This is what people call an agent. Claude Code is aimed at developers first, but it is also useful for automating repetitive work on files. We use it every day to build websites and automations. To go further, we listed lesser-known Claude Code commands.
ChatGPT vs Claude vs Claude Code: what is the difference?
| ChatGPT | Claude | Claude Code | |
|---|---|---|---|
| Company | OpenAI | Anthropic | Anthropic |
| What it is | A chat assistant | A chat assistant | An agent that works on the computer |
| How you use it | You type, it answers | You type, it answers | You describe a task, it carries it out |
| Who it is for | Everyone | Everyone | Mostly people who build websites, software or automations |
| Free version | Yes | Yes | No (paid plan or developer account) |
Are ChatGPT and Claude free?
Both have a free version, which is enough to get started. Paid plans give you more usage and extra features. For Claude, the pricing page checked on October 18, 2026 shows:
| Claude plan | Listed price | Includes Claude Code |
|---|---|---|
| Free | $0 | No |
| Pro | $17 a month billed annually, $20 billed monthly | Yes |
| Max | From $100 a month | Yes |
Prices can vary by country and taxes. OpenAI also offers a free ChatGPT plan and several paid plans: check its pricing page, which we could not verify directly for this article.
What should you always double-check when using AI?
An AI can be wrong with total confidence. Anthropic says so in its own documentation: even the most advanced models "can sometimes generate text that is factually incorrect". This is called a hallucination: a fluent, convincing and false answer. It can make up a number, a source, a law or a name.
- Check anything that matters: a price, a date, a legal or tax rule, health advice. Ask for the source, then open it.
- Reread before sending: an email to a client, a quote, a post.
- Be careful what you paste: avoid passwords, your clients' personal data or confidential documents, especially on a free plan whose terms you have not read.
The rule we follow. AI drafts, a human approves anything that commits the business: a price, a reply to a complaint, a message to a client.
Will AI replace us all?
It is a common question, often asked with some worry. Nobody can predict the future with certainty, and you should be wary of anyone who claims to, in either direction. What we see today is more down to earth: AI mostly replaces tasks, not whole people. Copying information from one tool to another, writing a first draft, sorting emails: that is where it saves time.
Adoption is still recent. In France, the 2026 France Num survey published by the government's Directorate General for Enterprise found that 40% of very small and mid-sized businesses now use AI tools, but only 11% use them to automate tasks. Most use it to produce content (34% generate text, voice or images); far fewer use it to automate.
Our view: the best way to worry less is to understand how it works and try it yourself. That is what this guide is for.
Where should you start with AI?
1. Create a free account
On ChatGPT or Claude, or both. The free version is enough to get started.
2. Try it on a real task
Pick something you actually do: rephrasing a tricky email, summarizing a long document, preparing questions before a meeting.
3. Give it context
The more you explain the situation (who you are, who the text is for, the tone you want), the better the answer. A one-line request gets a generic answer.
4. Check, then try again
Reread, correct, ask for another version: it works best as a back-and-forth.
5. Move on to automation when it helps
When a task comes back every day, AI can also handle it on its own, inside your tools. We collected examples in AI agent use cases for business, and the real cost in how much an AI agent costs. If you want to know what could be automated in your business, we can talk it through on a free 30-minute call.
Sources checked on October 18, 2026
- CNIL, definition of artificial intelligence (in French)
- Anthropic, Claude pricing page
- Anthropic, Claude Code documentation
- Anthropic, company page
- Anthropic, introducing Claude (March 14, 2023)
- Anthropic, documentation on hallucinations
- DGE, France Num 2026 survey (September 28, 2026, in French)
Frequently asked questions
What is AI, in one sentence?
Artificial intelligence is software that learned to perform a task from a huge number of examples, instead of following rules a human wrote one by one.
What is the difference between ChatGPT and Claude?
They are two competing AI assistants: ChatGPT is made by OpenAI, Claude by Anthropic. They do the same kind of work (writing, summarizing, analyzing, coding) and differ in the style of their answers, their features and their pricing.
What is Claude Code?
Claude Code is an Anthropic tool that lets Claude work directly on a computer: it reads and edits files, writes code and runs commands, instead of only answering in a chat window.
Is Claude free?
Claude has a free plan. The Pro plan costs $17 a month billed annually or $20 billed monthly, according to the pricing page checked on October 18, 2026. Claude Code is included in the Pro and Max plans, not in the free plan.
Can you trust an AI's answers?
Not blindly. An AI can make up a fact, a number or a source with total confidence: this is called a hallucination. Check anything that matters and reread before sending.
Will AI replace my job?
Nobody can predict that with certainty. Today, AI mostly replaces repetitive tasks (copying, sorting, writing a first draft) rather than whole jobs. Understanding it and trying it is still the best way to prepare.