COM,DCOM,DLL

COM:

Component Object Model Microsofts standard for distributed objects, an object encapsulation technology that specifies interfaces between component objects within a single application or between applications. It separates the interface from the implementation and provides APIs for dynamically locating objects and for loading and invoking them .

DCOM:

Distributed Component Object Model?Microsoft?s protocol that enables software components to communicate directly over a network in a reliable, secure, and efficient manner. DCOM is based on the DCE-RPC specification and works with both Java applets and ActiveX components through its use of the COM.

DLL:
A DLL (Dynamic Link Library) is a file that can be loaded and executed by programs dynamically. Basically it's an external code repository for programs. Since usually several different programs reuse the same DLL instead of having that code in their own file, this dramatically reduces required storage space. A synonym for a DLL would be library.The Dynamic Linked Library (DLL) is a compiled and linked collection of computer functi ons that are not immediately bound to an executable, but are called during program execution. Dynamic linking means that the data in a library is not copied into a new executable or library at compile time, but remains in a separate file on disk.