The Applications HWM component tracks the highest number of applications that have been connected to a database since it was restarted or performance counters were reset.
The maximum number of concurrent connections allowed is controlled by the MAXAPPLS configuration parameter. If the number shown by the Applications HWM component is close to the maximum set with the parameter, you might want to increase the parameter setting. When the parameter is set to AUTOMATIC, an unlimited number of connections is allowed.
At each refresh, Spotlight captures the statistic showing the highest number of applications.