In-proc server is a COM component, when instance is the

server is loaded into the caller process space. In-Proc

server can be easily identified by .dll extension.

Out-of-Proc server is a COM component that run in its own

process space and for any instances created by the users, a

proxy is created within the users process space. Proxy is

responsible for interacting with the server to carry out

operation on behalf of the client. (.exe extension).