Also called
link editor and
binder, a linker is a
program that combines object
modules to form an executable program. Many
programming languages allow you to write different pieces of
code, called
modules, separately. This simplifies the programming task because you can break a large program into small, more manageable pieces. Eventually, though, you need to put all the modules together. This is the job of the linker.
In addition to combining modules, a linker also replaces symbolic addresses with real addresses. Therefore, you may need to link a program even if it contains only one module.