The SAM database lives in the Registry under the HKLM\SAM key. Windows 2000 still uses the SAM for storing local account and policy information. However, unlike previous versions of Windows NT, Windows 2000 stores all domain account and policy information in the active directory.
The active directory (AD) is one huge, hierarchical, object-oriented information store that is shared across a domain (or domain forest). All account and policy information relating to the network as a whole is stored in the AD. I discuss the AD in great detail in Chapter 16, "SSPI."