What deals with local user and accounts group in windows server 2008?

All the users, Accounts and other organizational units which exist in the active directory are stored in the database file.
When you synchronize the domain controller at different site or locations then only this database file is syncronize and all the users, accounts and policies are implemented in all the domian controller.

1- Three types of user accounts exist in Windows Server2008: local user accounts, domain user accounts, and built-in user accounts.
Local user accounts reside on a local computer and are not replicated to other computers by Active Directory.
Domain user accounts are created and stored in Active Directory and replicated to all domain controllers within a domain.
Built-in user accounts are automatically created when the operating system is installed and when a member server is promoted to a domain controller.
2- The Administrator account is a built-in domain account that serves as the primary supervisory account in Windows Server2008.
It can be renamed, but it cannot be deleted.
The Guest account is a built-in account used to assign temporary access to resources.
It can be renamed, but it cannot be deleted.
This account is disabled by default and the password can be left blank.
3- Windows Server2008 group options include two types, security and distribution, and three scopes, domain local, global, and universal.
4- Domain local groups are placed on the ACL of resources and assigned permissions.
They typically contain global groups in their membership list.
5- Global groups are used to organize domain users according to their resource access needs.
Global groups are placed in the membership list of domain local groups, which are then assigned the desired permissions to resources.
6- Universal groups are used to provide access to resources anywhere in the forest.
Their membership lists can contain global groups and users from any domain.
Changes to universal group membership lists are replicated to all global catalog servers throughout the forest.
7- The recommended permission assignment strategy places users needing access permissions in a global group, the global group in a universal group, and the universal group in a domain local group and then assigns permissions to the domain local group.
8- Group nesting is the process of placing group accounts in the membership of other group accounts for the purpose of simplifying permission assignments.
9- Multiple users and groups can be created in Active Directory using several methods.
Windows Server2008 offers the ability to use batch files, CSVDE, LDIFDE, and WSH to accomplish your administrative goals.