What is The Linker?

When programs were written in the past often the development computer was not powerful enough to hold the entire program being developed in memory at one time. Historically, programs had to be divided into separate modules where each module would be compiled into object code and a linker would link the object modules together. Our development machines today are very powerful and the use of a linker is no longer absolutely necessary.

Many implementations of C provide function libraries which have been precompiled for a particular computer. These functions serve common program needs such as serial port support, input/output, and description of the destination computer. Functions within libraries are usually either linked with modules which use them or included directly by the compiler if the compiler supports library function inclusion.

When your program has been pre-processed, compiled and linked, the destination computer will be able to read and execute your program.