An ABL WebApp implements a server-side resource that provides OpenEdge data and operations for access by a resource client through the agency of an ABL Service. This resource is implemented by an ABL Business Entity, which is typically an ABL user-defined class that is coded to access the data through methods that implement the resource operations.

An ABL Service is a Data Object Service Catalog. This Data Object Service Catalog defines the schema of the data and the operations on the data that is supported by one or more ABL resources. In this way, a single ABL Service can support client access to multiple resources running on a single PAS for OpenEdge instance.

Progress Developer Studio for OpenEdge provides wizards and other tools to accelerate the development of server-side ABL Services

You can develop ABL Services using ABL Web App projects that support ABL Service development using facets that work with PAS for OpenEdge only. For more information on working with the ABL Web App project and creating ABL Data Object Services, see the Learn About PAS for OpenEdge help.