The Linker is the system program that combines the code of target programs with codes of other programs and library routines.
To facilitate linking, the language translator builds an object module which contains both target code and information about other program and library routines.
The linker extracts this information from the object module and combines them with the target code of the program to produce a program in machine language that can execute without requiring the assistance of any other program. Such a program is called as binary program.