The AppServer is an application server component that runs ABL procedures in response to direct client requests over a network. It helps you to build complex distributed applications by allowing a client application to call ABL procedures or user-defined functions remotely as if they were running locally on the client machine. A remote procedure or remote user-defined function is thus a procedure or function that runs in an OpenEdge (AppServer) session that is separate from that of the client, and typically on a separate machine from the client. In an ABL client, you access and invoke a remote procedure or user-defined function using a variation of the RUN statement or the FUNCTION statement (and function invocation). In an Open Client or Web service client, you invoke the remote procedure as a method on an object defined by the Open Client or OpenEdge Web service interface.
OpenEdge supports Web services in two basic ways:
Producing Web services from AppServer application services
Consuming industry Web services from within an ABL client