1. The Compilation Process

Compilation is the process of converting human-readable code (High-Level Language) into machine-readable code (Binary). This happens in four distinct stages:

• Preprocessing: The preprocessor handles directives starting with # (like #include). It expands macros and includes the contents of header files into the source code.

• Compilation: The expanded code is translated into Assembly Level Language, which is a low-level instruction set specific to the computer's processor.

• Assembly: An assembler converts the assembly code into Object Code (machine code), usually resulting in a .obj or .o file.

• Linking: The linker combines your object code with library files (like stdio.h functions) to create a single Executable File (e.g., .exe on Windows or .out on Linux).

2. The Execution Process

Once the executable file is created, the execution phase begins:

1. Loading: When you run the program, the Operating System's Loader brings the executable file from the hard drive into the RAM (Random Access Memory).

2. Entry Point: The CPU starts executing instructions beginning at the main() function.

3. Instruction Cycle: The CPU follows the "Fetch-Decode-Execute" cycle for every line of code until the program hits a return statement or the end of main().

Summary Table