Source code facts for kids

In computer programming, source code is like a recipe or a set of instructions for a computer. It's usually a text file that tells the computer exactly what to do. Imagine you want to bake a cake; you follow a recipe. A computer program follows its source code!

People write source code using special languages called programming languages. These languages are designed so humans can read and understand them. A big computer program might have many different source code files that all work together to make the program run.

When the source code is finished, it's often compiled. This means a special program, called a compiler, translates the human-readable code into a language the computer understands much faster, like machine language. This machine language is very hard for humans to read, but it's perfect for the computer.

What is Source Code?

Source code is the original set of instructions that programmers write. It's the blueprint for any software or app you use. Without source code, computers wouldn't know how to do anything, from playing a game to browsing the internet.

How Computers Understand Code

Computers don't understand English or Spanish directly. They understand very basic commands, like "turn this on" or "add these numbers." Programming languages act as a bridge. You write in a language like Python or C++, and then a compiler or interpreter translates your instructions into the computer's language. This translation makes the program run quickly and efficiently.

Open Source vs. Closed Source

Some computer programs are open source. This means their source code is available for anyone to see, learn from, and even change. It's like sharing a recipe so others can try it or make their own versions. Many popular tools, like the Firefox web browser or the Android operating system, are open source.

Other programs are closed source. For these, only the people who created the program can see and change the source code. When you download a closed-source program, you usually only get the finished, compiled version that the computer can run. This is common for many games and commercial software.

Example of C Source Code

Here's a simple example of source code written in a programming language called C:

#include <stdio.h>
int main()
{
      printf("Hello world!\n");
      return(0);
}

When a C compiler translates this code and the computer runs it, it will simply display the words "Hello world!" on the screen. Then, the program will finish. This is often one of the first programs new coders learn to write!

See also

• In Spanish: Código fuente para niños