The Single Domain Model consists of a single domain. It is the simplest to understand and the easiest to implement administer. All accounts reside on one PDC and access to resources is granted to individuals and groups within that domain.
The performance of a Single Domain can become a serious problem as the number of accounts increase. NT Workstations, NT Servers, BDCs, and the PDC all create accounts within the domain in addition to the accounts that an administrator will create for individual users and groups.
The Microsoft Windows NT Virtual Lecture by
Florida Community College at Jacksonville