Static library and dynamic library distinction in C++?

In the case of a static library (.lib file), the linker looks for all the functions which your application references and merges the code for those functions into the compiled application itself.

In contrast, a dynamic link library (.dll) remains separate from the application. The latter just contains sufficient information to enable it to call the appropriate .dll functions at runtime.

The advantages of static libraries are:

1. You only need to distribute your application - you don't need to distribute the .lib file as well.

2. As the .lib file is part of your application, versioning is not a problem - you always have the correct version built in.

The disadvantages are :

1. If you use the static library in more than one application, you're wasting disk space because each application contains a copy of the library.

2. If you want to use an updated version of the .lib file, then you have to recompile and redistribute your application.

As .dlls are not part of your application, they have to be loaded at runtime and the appropriate functions then need to be referenced.

An 'import library' is a small .lib file which automates this process and which usually has the same name as the .dll. The import library is linked into your application at compile time in the usual way and you can then call the .dll functions as though they'd been statically linked.