What is Active directory?

Active Directory is a database that keeps track of all the user accounts and

passwords in your organization. It allows you to store your user accounts and

passwords in one protected location, improving your organization's security.

Why Active Directory?

-The NTDS.DIT (New technology directory service) and The DIT stands for Directory Information Tree: is The Active Directory database. This is used to

store ALL active directory-specific information.

-LDAP: LDAP stands for Lightweight Directory Access Protocol .In Windows Server LDAP is a protocol which is used for access Active

Directory object, user authentication, and authorization. It is used in Active Directory for communicating user queries .e.g. LDAP can be

used by users to search and locate a particular object like a laser printer in a domain.

- Kerberos : is a computer network authentication protocol which works on the basis of 'tickets' to allow nodes communicating over a non-secure

network to prove their identity to one another in a secure manner.

Domain: a group of computers and devices on a network that are administered

as a unit with common rules and procedures.

Tree

A forest is a collection of trees that don’t necessarily form a contiguous namespace (although each tree must be contiguous). This

arrangement might be useful if your company has multiple root DNS addresses

Forest: At the top of the structure is the forest. A forest is a collection of trees that share a common global catalog (that contains specific information

about every object in the forest), directory schema, and logical structure. The forest represents the security boundary within which users, computers,

groups, and other objects are accessible.

Organizational Unit: An organizational unit (OU) is a container within a Microsoft

Active Directory domain which can hold users, groups and computers. It is the smallest

unit to which an administrator can assign Group Policy settings.

- Different geographical units

- Same domain

- Different IP subnets