Users with SuperUser permissions can create quotas for individual users or quotas for groups.
Group quotas can be set for Active Directory users. If a group of ten users are given a quota of 1 TB of storage and one of the ten users fills the entire terabyte, then the entire group will be in excess of the quota and none of the ten users will be able to use any of the storage associated with their group.
An individual user's quota is set for only the individual. Once the individual user has used up all of his or her storage or runtime quota, the user will be in excess of the quota and the user will no longer be able to use the storage associated with his or her quota.