The role of ESE in an active directory is to store and retrieve data through indexed and sequential access.Its the data storage technology from Microsoft.
Active Directory's database engine is the Extensible Storage Engine ( ESE )
help to manage resources of organization
DomainDNSzones
The role refers to the service or services that the server is providing, such as DHCP, DNS, HTTP, etc.
1 for each active directory (AD) site
The DNS Server Role and the active directory is not installed till the adds service is started on the server 2008.if the service is not started(one needs to check the option under roles of the server)the active directory installation wont happen.this feature is only in 2008 not in 2003.The active directory works as service in 2008
The Active Directory configuration partition is a critical component of the Active Directory architecture that stores configuration data for the directory service itself. It contains information about the Active Directory forest, including the schema, replication topology, and services available within the forest. This partition is replicated across all domain controllers in the forest, ensuring that every controller has consistent configuration information. It plays a key role in enabling the functionality and management of Active Directory environments.
For the best performance, when an Active Directory organization contains more than 20,000 objects, you should upgrade to 64-bit. Upgrading servers that run Active Directory domain controllers and the global catalog to 64-bit improves the overall performance and scalability of your Exchange Server 2007 environment. However, 32-bit domain controllers are still supported. Lookup and response times between the Exchange 2007 categories and the Active Directory directory service will improve with the use of 64-bit. The size of the Extensible Storage Engine (ESE) database that holds Active Directory can frequently be larger than 3.0 gigabytes (GB). This prevents caching of the contents of the whole database, and therefore increases lookup and response times. By using 64-bit, the available RAM for caching can be increased beyond 4.0 GB. This is large enough to cache the whole ESE database, even for large Active Directory organizations, and will improve Exchange 2007 lookup and response times.
1 for each active directory (AD) site
The Active Directory administrative tools can only be used from a computer with access to a domain. The following Active Directory administrative tools are available on the Administrative Tools menu: Active Directory Users and Computers (dsa.msc) Active Directory Domains and Trusts (domain.msc) Active Directory Sites and Services (dssite.msc)
DHCP
The main benefits of using an active directory like LDAP Active Directory are many. One can use an active directory to allow for scheduling to made and updated in a timely manner.