)To transform a program written in a high-level programming language from source code into object code. Programmers write programs in a form called source code. Source code must go through several steps before it becomes an executable program. The first step is to pass the source code through a compiler, which translates the high-level language instructions into object code.
The final step in producing an executable program -- after the compiler has produced object code -- is to pass the object code through a linker. The linker combines modules and gives real values to all symbolic addresses, thereby producing machine code.