scheduledTimerWithTimeInterval vs. timerWithTimeInterval

I’ve used the former without any problems in my programs and it always works to expectations. But in looking through the documentation and other examples form this site, I see lots of reference to using the latter. The documentation indicates that “scheduled” means it adds it on the current run loop in default mode, but I have no idea what that means. Anyone want to elaborate for me? Any help is appreciated.


scheduled timers are automatically added to the run loop, unscheduled timers are not.
The timer functionality is the same.

see the section Using Timers of Timer Programming Topics

So if a timer is not part of the default run loop (timerWithTimInterval) what triggers it?

the method addTimer:forMode: of NSRunLoop