Compilers & linkers

Do I need to install a compiler?

We will discuss installing a compiler shortly, so there is no need to do so now.
After the compiler creates one or more object files, then another program called the linker kicks in.
The job of the linker is three fold:

First

to take all the object files generated by the compiler and combine them into a single executable program.

How does a linker work?

For most compilers, each object file is the result of compiling one input source code file.
When a program comprises multiple object files, the linker combines these files into a unified executable program, resolving the symbols as it goes along.
Linkers can take objects from a collection called a library or runtime library.

What is the difference between a compiler and a linker?

A compiler generates object code files (machine language) from source code.
A linker combines these object code files into an executable.
Many IDEs invoke them in succession, so you never actually see the linker at work.
Some languages/compilers do not have a distinct linker and linking is done by the compiler as part of its work.

What is the difference between a linker and a preprocessor?

Linking:

the linker takes the object files produced by the compiler and produces either a library or an executable file.
The preprocessor handles the preprocessor directives, like #include:and #define.
It is agnostic of the syntax of C++, which is why it must be used with care.