Schedules are specified intervals at which the source has to poll data and publish them as events. You can schedule only the pull sources.
The schedules can either be Static or Dynamic.
Static Schedule
A static schedule generates events on a schedule that you set, such as one time every 30 minutes. An example of a static schedule is an RSS or Atom News Reader service that extracts events from an RSS news feed.
Dynamic Schedule
The dynamic schedule waits for a configured period after the previous task has completed before running again. You can configure the time interval to wait between the executions. The dynamic schedule ensures that there is no overlapping of queries while executing the same instance of the source task.