Basics

A DLL (Dynamic Link Library) is a collection of routines in a file which is loaded on demand by the Windows kernel.

The DLL principle allows the routines (procedures) contained within it to be "bound" (linked) to the executable at the time the application is run. Furthermore, several applications can use the DLL routines without requiring multiple copies to be installed on the system.

Of course, procedures of one DLL can also call procedures of other DLLs, as is regularly done by Windows.

List & Label uses different DLLs for specific jobs.