Overview of COM

COM allows the reuse of objects across different software and hardware environments to interface with each other, without the knowledge of its internal implementation. COM is a proprietary standard and is commonly associated with Microsoft's COM. COM forms the basis for Microsoft's other technologies, including ActiveX, COM+, and Document Component Object Model (DCOM).

COM allows an object to be created in several languages, such as C, C++, Visual Basic, Delphi, or Python. Using COM-aware components, COM classes are built as binary standards. Each COM component has its own class identifier (CLSID), which are globally unique identifiers (GUIDs), used for identification when used on a runtime framework. To locate a COM library, the Microsoft Windows registry is used to list all the available class and interface libraries as GUIDs.