Course IntroductionLesson 2 of 6

What is Claude?

A simple, clear introduction to Claude — who made it, what it can do, and how it compares to other AI tools you may already know.

The Simple Answer

Claude is an AI assistant — a computer program you talk to in plain language. You type (or speak) what you need, and Claude reads it, thinks about it, and writes back a useful answer.

It was created by a company called Anthropic, founded in 2021 by former members of OpenAI. Anthropic focuses on building AI that is safe, honest, and helpful — and those three values are central to how Claude behaves.

🧠
Claude by Anthropic
Available at claude.ai - Built on Constitutional AI principles - Safe & honest by design

How It Actually Works

Claude is a Large Language Model (LLM). In simple terms, it was trained on a huge amount of text — books, articles, code, and more — and learned patterns in how language works. When you send a message, it predicts the most helpful continuation of that conversation.

You do not need to understand the technology to use Claude well. Think of it the same way you use Google Search — you don't need to know how it crawls the web, you just need to know how to ask a good question.

✍️You type a message
⬺
🔄Claude reads & thinks
⬺
💬Claude writes a reply

How every Claude interaction works

See It in Action

Here are two real examples of talking to Claude — one simple, one more complex.

Example 1 — A simple question

claude.ai
Explain what inflation means in simple words.
C

Sure! Inflation is when the prices of things go up over time.

For example: if a cup of coffee cost ₹20 last year and now it costs ₹22, that's inflation. Your money buys slightly less than it did before.

Governments measure inflation using a "price basket" — a set of everyday items — and track how much the total cost changes each month.

Claude gives a clear, beginner-friendly explanation with a real example

Example 2 — A coding task

claude.ai
Write a Python function that checks if a number is prime.
C

Here's a clean Python function to check if a number is prime:

# Returns True if n is prime, False otherwise
def is_prime(n: int) -> bool:
if n < 2:
return False
for i in range(2, int(n**0.5) + 1):
if n % i == 0:
return False
return True

It checks divisibility only up to √n, making it efficient.

Claude writes working, well-commented code and briefly explains the approach
Notice: You didn't need to use any special commands or syntax. Just plain English — and Claude handles the rest.

What Claude Can (and Cannot) Do

✅Claude can
  • ✓Answer questions on almost any topic
  • ✓Write, review, and debug code
  • ✓Summarise long documents
  • ✓Draft emails, essays, and reports
  • ✓Explain complex ideas simply
  • ✓Translate between languages
  • ✓Analyse data and spot patterns
  • ✓Help brainstorm ideas
⚠️Claude cannot
  • ✕ Browse the live internet (without plugins)
  • ✕ Remember past sessions — each new chat starts fresh
  • ✕ Take actions on your computer (without Cowork)
  • ✕ Guarantee 100% factual accuracy — always verify
  • ✕ Access private data it was not given
  • ✕ Replace professional advice (medical, legal, etc.)

The Three Claude Models

Claude comes in three sizes. Each is better suited to different tasks. You can switch between them at any time in the settings.

🐦
Claude Haiku
Fast & lightweight
Speed5/5
Power2/5
  • ✓Quick Q&A
  • ✓Simple summaries
  • ✓Real-time chat apps
🎵
Claude Sonnet
Best for most tasks
Speed4/5
Power4/5
  • ✓Writing & coding
  • ✓Analysis
  • ✓Day-to-day work
🎼
Claude Opus
Most powerful
Speed2/5
Power5/5
  • ✓Complex reasoning
  • ✓Research tasks
  • ✓Long documents
Recommendation for beginners: Start with Claude Sonnet. It gives you the best balance of speed and capability for everyday tasks.

Claude vs Other AI Tools

You may have heard of ChatGPT or Gemini. Here's a simple comparison so you know where Claude fits.

FeatureClaudeChatGPTGemini
Made byAnthropicOpenAIGoogle
FocusSafety & honestyCapability & toolsGoogle integration
Long documents⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐
Coding⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐
Free tierYesYesYes
All three are excellent tools. This course focuses on Claude because of its strong performance on long documents, coding tasks, and its straightforward, honest communication style.

Key Takeaways

  • 🧠Claude is an AI assistant made by Anthropic, designed to be safe, honest, and helpful.
  • 💬You talk to it in plain language — no special commands or technical knowledge needed.
  • 🐦Three model sizes: Haiku (fast), Sonnet (balanced), Opus (powerful). Start with Sonnet.
  • ✅Claude is excellent at writing, coding, summarising, and explaining — but always verify important facts.
  • 🚀The best way to learn Claude is to simply start using it. The rest of this course will show you how.

What's Next

Next: creating your account and sending your first message to Claude — takes about 5 minutes.