What you’ll learn in this lesson

• What coding actually is, in plain words
• What a programming language does for you
• What you will be able to make by the end of this course
• How this course works, lesson by lesson

What coding actually is

Coding is writing instructions for a computer to follow. That is the whole idea. You write the instructions in a language the computer understands, and the computer carries them out, one step at a time, exactly as written.

You already give instructions like this every day. A recipe is a list of instructions for making food. Directions to a friend’s house are instructions for getting somewhere. Coding is the same skill, aimed at a computer instead of a person — except the computer is extremely literal. It does exactly what you wrote, not what you meant. That is why learning to code is mostly learning to be clear and precise.

A program is a finished set of instructions saved as a file. When you “run” a program, the computer follows the instructions in it from top to bottom.

What a programming language does for you

A programming language is a simplified way of writing those instructions. Computers really only understand numbers, but nobody wants to write programs as numbers. A language like Python lets you write instructions in words that look a lot like plain English, and Python turns them into the numbers the computer needs.

Python is a good first language for three reasons. First, it reads much like English, so you spend your energy on ideas, not on strange symbols. Second, you can get something working in minutes — your very first program is one line long. Third, it is a real language used by professionals for websites, data work, games, and AI tools, so what you learn here is not a toy version of coding. It is the real thing, taught from the beginning.

Here is a complete Python program. It is one line:

print("I am learning to code!")

Output:

I am learning to code!

print is an instruction that means “show this on the screen.” The words inside the quotes are the message. You will write your own version of this in Lesson 3.

What you will make in this course

By the end of this course, you will be able to:

• Write programs that print messages, do arithmetic, and remember values.
• Make decisions in a program (“if this, do that”) and repeat actions with loops.
• Store collections of things in lists and dictionaries.
• Draw shapes and pictures with code.
• Build a working number-guessing game from scratch.

That last one is the course’s mini-project in Lesson  16. You will write every line of it yourself, using only the ideas from the earlier lessons. It is a small game, but it is a real program — and once you can build one real program, you can build the next one.

How this course works

Each lesson follows the same shape, so you always know what is coming:

1. Learn — a short explanation with code you can try yourself.
2. Try it — a small hands-on exercise with an expected result, so you can check your own work.
3. Quick quiz — five short questions with an answer key.
4. Key takeaways — the ideas worth remembering.

You need no experience at all to start. If you can type and use a computer, you are ready. The only tool you need is Python itself, which you will install in the next lesson.

One habit to start now: when something does not work, read the message the computer gives you. It is usually pointing at the exact problem. Errors are not failures — they are how every programmer, beginner or professional, finds out what to fix next.

print("I am learning to code!")

Output:
I am learning to code!

Download the Lesson 1 slides (PowerPoint, with narration)

Download the Lesson 1 slides (PDF)

Hands-on exercise

1. In your own words, explain what a program is to someone who has never heard the word.
2. Look at the one-line program above. What do you think would happen if you changed the words inside the quotes to your own name?
3. Write down one thing you would like to make with code someday. Keep it — you will be surprised how soon it becomes reachable.

1. Say: “Hello!”
2. Pick up the apple.
3. Put the apple in the box.
4. Say: “Done!”

Press Run to see the robot follow the instructions.

Practice file

Save this as lesson01-practice.py and run it with F5 in IDLE.

# Lesson 1: Welcome — What Coding Is
# WHAT TO DO: A program is a list of instructions the computer follows
# from top to bottom. This program lists three steps, but step 2 is
# unfinished. Fill in line 11: replace the placeholder words inside the
# quotes with a real second step of your own.
# HINT: Step 2 could be anything a beginner does next, for example
# "Type your first program." Keep it inside the quotes.
# Run with F5 in IDLE. You are done when all three steps read sensibly.

print("Step 1: Open Python.")
print("Step 2: TODO - fill in this step")  # <-- CHANGE THIS LINE
print("Step 3: Run your program.")

Key takeaways

• Coding is writing instructions for a computer to follow, exactly as written.
• A program is a saved set of instructions; running it means the computer follows them from top to bottom.
• Python reads much like English and is a real professional language, not a toy.
• By the end of this course you will build a working number-guessing game.
• Errors are normal: read the message, find the problem, fix it, and move on.

Next lesson: What Is Python, and Installing It.

Quick quiz

1. What is coding?
2. What is a program?
3. What does a programming language do for you?
4. Why is Python a good first language?
5. What will you build in this course's mini-project?

Answer key: 1. Writing instructions for a computer to follow. 2. A finished set of instructions saved as a file. 3. It lets you write instructions in readable words instead of numbers, and turns them into what the computer needs. 4. It reads much like English, you can get something working in minutes, and it is a real professional language. 5. A number-guessing game.