Computer Science Basics for Beginners

⚙️ From Code to Output – How Programs Run?

Have you ever wondered what happens between writing code and seeing results on the screen? This chapter explains the complete journey of a program — from writing it to watching it work.

📝 Step 1: Writing the Code (Source Code)

The process starts when a developer writes code in a programming language like Python, C, or Java. This is called source code.

# Python Example
print("Hello, World!")
  

🔄 Step 2: Translating Code (Compilation / Interpretation)

Since computers don’t understand human-readable languages, the source code must be converted to machine code (binary).

• Compiler: Translates all at once (e.g., C, C++)
• Interpreter: Translates line-by-line (e.g., Python)
• Hybrid: Compiles to bytecode, then interprets (e.g., Java)

💾 Step 3: Machine Code Execution

Once translated, the instructions are in a language the CPU understands — binary (1s and 0s). These instructions are then executed.

• CPU: Performs arithmetic and logic operations
• RAM: Stores temporary data and instructions while running
• Storage: Used if needed (e.g., reading files)

🖥️ Step 4: Output is Displayed

Once the CPU finishes processing the instructions, the result is shown to you — on the console, screen, or file.

Hello, World!
  

🧠 Summary Flow (For Beginners)

1. You write code
2. Compiler/Interpreter translates it
3. CPU executes translated instructions
4. Output is shown

🧠 Real-Life Analogy

Think of writing code like writing a cooking recipe. The compiler is the translator turning your recipe into a shopping + cooking guide for the chef (CPU). The final dish is the output!

🧪 Tools Involved in Running Code

• Text Editor/IDE: VS Code, Sublime, PyCharm
• Compiler or Interpreter: Converts code to machine code
• Terminal or Console: Where output is shown

📝 Practice Questions

1. What is source code?
2. List the steps involved in running a program.
3. What happens during the compilation stage?
4. How does the CPU interact with RAM and Storage?

✅ Coming Next

In the next chapter, we’ll explore IDEs, Editors & Terminal Basics — the tools you’ll use every day to write, run, and manage code.