Who are the participating components in Broker Architecture?

Answer:

Server
Objects that expose their functionality through interfaces conforming to Interface Definition Language (IDL) or through a binary standard specific for the Broker

Clients
Applications that access the services of at least one server by forwarding requests to the Broker

Proxies
Components that hide the communication details by exposing the same object oriented interface as client and server
Bridge
This is an optional component used for integrating two brokers across different heterogeneous network