If you need to set a daily reminder to take medicine at 9am, 12pm and 4pm, you can set three separate daily reminders, but it would be neater to have one daily reminder with three alerts or "sub-reminders" (something akin to Samsung Calendar App alerts, or the iPhone Reminder alerts).
What's the difference? It's essentially the same thing, since you'd have to set the times of the "sub-reminders" the same way you would for the separate doses.
