What's the difference between the online time and the system up time in the output from the display wlan ap name verbose command?

What's the difference between the online time and the system up time in the output from the display wlan ap name verbose command?

 The output from the display wlan ap name verbose command is shown as follows:

<Sysname> display wlan ap name ap1 verbose

AP name                       : ap1

AP ID                         : 1

AP group name                 : default-group

State                         : Run

Backup Type                   : Master

Online time                   : 0 days 1 hours 25 minutes 12 seconds

System up time                : 0 days 2 hours 22

Online time shows the duration that the AP has been associated with the AC.

System up time shows the duration that the AP has operated since the most recent startup.