Type Library

A binary version of an Interface Definition Language (IDL) file, providing complete information about the interfaces of a COM object. A type library contains a binary description of the interfaces exposed by a component, defining the methods along with their parameters and return types.

Type libraries exist in one of these forms:

  • Built into existing COM objects. This is the preferred method of declaring type libraries, and the Associations editor in Microsoft® Visual Studio® Installer provides an easy way to associate COM objects with their type libraries.

  • As stand-alone type library (.tlb) files.