Certain resource/attendees are invited only for certain parts of the big meeting /event - within Single meeting request
To create a single meeting request, where certain attendees or resources (eg rooms) are required/attending the meeting only for part of the time.
Thus resources can be blocked only for the required time slot than having to be blocked for the entire meeting schedule.
This brings in clarity on who is needed at what time and to free up resources, without having to create multiple agenda entries for the same meeting.
Feature is non-existent in OWA, Windows, Mac, iOS