Members, and if you allow it, the public can make a booking.
Actually by “members” in this context we mean anyone in the Member Database, and a member class that allows them to login and to make bookings.
Once a booking is made, here is what an Administrator can do (your login needs the BOOKINGS role):
Edit almost any aspect of the booking.
Move people in the booking into or out of beds and rooms using the Allocate Rooms screen.
Change the price of the booking.
Receipt a payment, or issue a refund.
The following settings are configured for you before you start using the Booking Service, but are mentioned here for reference. Access to make a booking is set using the Role BOOKINGS_MAKE (see admin menu -> admin -> roles). You can give this role to Members or to Public (or even to an administration level, if you don’t want members to be able to book themselves, perhaps temporarily). Separately to this, the Configuration Item ONLY_MEMBER_MAKE_BOOKING can be turned on if you require an account to be associated with each booking. By account, we mean a login given via the Member Database. An administrator who has the role ONLY_MEMBER_MAKE_BOOKING (same name) can override this rule and make a booking not associated with any login.
Note that it’s possible for an Administrator to make a booking for somebody that they can’t make for themselves. For example, an entry in the Member Database that has a member class that cannot login, but that can book.