Compilers convert high-level programming languages like C and C++ into machine-level language. The compilation process involves preprocessing, compilation, assembly, and linking of the source code. After linking, an executable file is created that can be loaded into memory and executed by the computer. Debugging is used to locate and correct errors in the code during development.

1. COMPILATION AND EXECUTION

2. INTRODUCTION
 First of all, computers are electronic device know
only one language that is machine language. i.e. it
contains only 0’s and 1’s
 so if you need to instruct a computer you need to
give instructions in binary form that is in the form of
0’s and 1’s.
 For a human it is very difficult to talk in this
language. So we create a software which will
convert our known language ( high level language)
into machine level language. thus computer can
work.
 This software is known as compilers.

3. COMPILERS
 Compiler is software which converts high level
language(C, C++ into machine level language. And
this process is known as compilation.
 After compilation we get a file known as object file
which is machine language. Object file can be
directly loaded into computer memory and execute
or run that. The process of loading object file and
running that file is known as Execution.

4. COMPILATION AND EXECUTION
 There are many steps involved in converting a C
program into an executable form, these all steps
are called "build process".
 Build process are representing in the following
graphically diagram :

6. LETS NOW UNDERSTAND THE STEPS MENTIONED IN
ABOVE FIGURE IN DETAIL.
 Editor-Type your program in editor (source code).
 Pre-processing-During this step, the C source
code is expanded based on the pre-processor
directives like as #include, #ifdef, #define etc. The
expanded source code is stored in an intermediate
file with .i extension.

7. STEPS DESCRIPTION CONTINUED..
 Compilation- The expanded source code is then
passed to the compiler, which identifies the syntax
error in the expanded source code. If the expanded
source code is error free, then the compiler transfer
the expanded source code in C, into an equivalent
assembly language program. The assembly code is
typically stored in .ASM file. So our first.c file would
be changed and stored in first.ASM.

8. STEPS DESCRIPTION CONTINUED..
 Assembling - Assembler translate the .ASM
program into Relocatable Object code. Thus
assembler translates our first.asm file into first.OBJ.
.OBJ file is one of the binary file. This object file
contained header and several sections.

9. STEPS DESCRIPTION CONTINUED..
 Linking - Linking is the final step of build process
i.e. creating an executable program. It's do
following works :
 Find definition of all external function
 Find definition of all global variables
 Combine Data Section
 Combine Code Section
 Loading - Once the .EXE file is created and stored
on the disk, it is ready for execution. When we
execute it, it is first brought from the disk into the
memory (RAM) by an OS component called
Program Loader.

10. PROGRAM DEBUGGING
 In software development, debugging involves
locating and correcting code errors in a computer
program.
 The debugging process starts as soon as code is
written and continues in successive stages as code
is combined with other units of programming to
form a software product.
 In a large program that has thousands and
thousands of lines of code, the debugging process
can be made easier by using strategies such as
unit tests, code reviews and pair programming.