Portable Object Adapter (POA) - The CORBA object responsible for splitting the server side remote invocation handler into the remote Object and its Servant. The object is exposed for the remote invocations, while the servant contains the methods that are actually handling the requests. The Servant for each object can be chosen either statically (once) or dynamically (for each remote invocation), in both cases allowing the call forwarding to another server.
On the server side, the POAs form a tree-like structure, where each POA is responsible for one or more objects being served. The branches of this tree can be independently activated/deactivated, have the different code for the servant location or activation and the different request handling policies.