An event that repeats consistently (weekly, monthly, etc.) is a Recurring Event. An event that repeats more sporadically has multiple Sessions.
Similar to Google Calendar, Recurring Events can happen daily, weekly, monthly, or annually. The Recurring Event feature is a quick and easy way to create multiple events with the same event details.
The new "Sessions" feature is designed for events such as movies or plays that have different start and end times, and/or occur on non-sequential days.
How to create an event with multiple "Sessions" >