A vApp (vCloud) reservation is a share of the memory, networking, and storage resources of a virtual datacenter that is allocated to a business group.
To provision vApps, a business group needs at least one vCloud reservation. Each reservation is for one business group only but a group can have multiple reservations on one compute resource or reservations on multiple compute resources.
The allocation model for a reservation depends on the allocation model in the associated virtual datacenter. Available allocation models are Allocation Pool, Pay As You Go, and Reservation Pool. For information about these allocation models, see thevCloud Director or vCloud Air documentation.
In addition to defining the share of fabric resources allocated to the business group, a reservation can define policies, priorities, and quotas that determine machine placement.