BBL :- Heart of all processes, it spawn , decays. It directs all communication traffic, sending data requests to the appropriate programs for processing.
WSL :- WorkStation Listener monitors the network for connect requests sent from windows clients. Once the connection is established, the WSL hands the client to a WSH process to handle the ongoing communication.
WSH :- WorkStation Handler maintains a persistent connection to the Windows client until requests for data have been satisfied.
JSL:- JoltStation Listener process monitors the network for connection requests sent from Java clients(typically processes running on Web Server). After the connection is established control is passed to JSH.
JSH:- Jolt Station Handler maintains persistent connection to the Java client until requests for data have been satisfied. The BBL tells the JSH which PeopleSoft process is the appropriate one to use.