# Listener Overview

Services coordinate their sessions with the help of a listener, a process on the server that receives connection requests on behalf of a client application. Listeners are configured to "listen on" protocol addresses for a database service or non-database service.

Protocol addresses are configured in the listener configuration file, listener.ora, for a database service or a non-database service.

- An Oracle8i database service automatically registers its information with the listener, such as its service name, instance name(s), and load information. This feature, called service registration, does not require service configuration in the listener.ora file.

- Other services, including an Oracle7 database, Oracle8 database, and the Oracle Enterprise Manager management tools, require service configuration in the listener.ora file.

Once the listener is configured, the listener can be managed with LSNRCTL.

| See Also: Chapter 7, Configuring the Listener, in the Net8 Administrator's Guide for more information about configuring the listener.