Containers and Servers
Compound document applications are of two basic types: container applications and server applications. OLE container applications provide users with the ability to create, edit, save, and retrieve compound documents. OLE server applications provide users with the means to create documents and other data representations that can be contained as either links or embeddings in container applications. An OLE application can be a container application, a server application, or both.
OLE server applications also differ in whether they are implemented as in-process servers or local servers. An in-process server is a dynamic link library (DLL) that runs in the container application's process space. You can run an in-process server only from within the container application.