If talking about the JDBC Adapter for example:
Adapter Notification: (Triggers a publish of a document possibly containing the data that has changed in the database table e.g. Insert/Update)
Adapter Service: (Allows you to make Inserts/Updates/Query the tables in your database)
e.g. An Update notification in one table by a client app, may trigger an update/insert of another table via an Adapter Service.
#Universal-Messaging-Broker#webMethods#Integration-Server-and-ESB#broker