The second database job is the DAMON data monitor job. The DAMON job runs the majority of the background processing and is responsible for running background cleanup processes required by the application that can potentially take a relatively long time to run.
Oracle and DAMON
By default, DAMON runs every Saturday. It uses the Oracle DBMS_SCHEDULER package to schedule the jobs; an Interval setting controls the schedule and accepts the same parameters as the DBMS_SCHEDULER interval. For more information, refer to your Oracle Database documentation.