Both actions lead to the same thing, a job runs and the workflow automation cycle completes. However, there is quite a difference between these two.
The trigger is caused by some action, such as a case or message creation. That means that anytime a case is created, the system checks if the conditions of that trigger are met.
On the other hand, the Scheduler, as the name suggests, is based on a time interval and runs periodically. For example, the system checks every hour whether the conditions of the scheduler are met.
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