The Application Server Defined Web servers alone are not enough to put a business online. Applications need to be written that encapsulate both the user interactions and the logic of the business enterprise. First, applications have to be deployed into the application server and then loaded for execution. All resources needed by the applicationdata sources and resource adaptorsare also loaded. In the world of application servers, data sources can mean many things. In most situations, the main data sources can be disparate databases, such as Oracle, Informix, Sybase, DB2, or Microsoft. Accessing data from data sources can be done via native database drivers or other back-end data sources like ERP systemsfor example, BEA Tuxedo or SAP R/3and transaction managers. For security services, application servers might communicate with authentication tools such as RADIUS or LDAP servers.

The Application Server Defined Web servers alone are not enough to put a business online. Applications need to be written that encapsulate both the user interactions and the logic of the business enterprise. First, applications have to be deployed into the application server and then loaded for execution. All resources needed by the applicationdata sources and resource adaptorsare also loaded. In the world of application servers, data sources can mean many things. In most situations, the main data sources can be disparate databases, such as Oracle, Informix, Sybase, DB2, or Microsoft. Accessing data from data sources can be done via native database drivers or other back-end data sources like ERP systemsfor example, BEA Tuxedo or SAP R/3and transaction managers. For security services, application servers might communicate with authentication tools such as RADIUS or LDAP servers.