Computer Programming Software Terms, Glossary and Dictionary
DLL: Dynamic-Link Library
Dynamic-link library (DLL) is Microsoft's implementation of the shared library concept in the Microsoft Windows operating systems. These libraries usually have the file extension DLL, OCX (for libraries containing ActiveX controls), or DRV (for legacy system drivers). The file formats for DLLs are the same as for Windows EXE files — that is, Portable Executable (PE) for 32-bit Windows, and New Executable (NE) for 16-bit Windows. DLLs can contain code, data, and resources, in any combination. DLL is files containing groups of often-used computer code which can be shared amongst many programs. This has several advantages: programmers who use library code do not need to keep reinventing the wheel; programs which invoke library code do not each need to include a copy of that code, making their files smaller; updates to library code can be applied in one place, rather than in many programs.