ACTIVE DIRECTORY BASICS:-

Active Directory utilizes two main standards. These are the X.500 standard and LDAP. X.500 uses by default  in AD.

LDAP (Light Weight Direct Access Protocol):-
 It is a communication protocol that allows to communicate between LDAP server and LDAP client(Non windows like Linux ,Solaris etc.).
It works on the port no 389.In it's first version it does not have enough security features.So it is called as Light weigt direct acces protocol.
LDAP Syntax:-

LDAP uses a syntax that refers to the most significant part first followed by less significant or precise parts afterwards. This is the opposite of other systems, like filenames or paths. The main syntax of any LDAP command is like this example: CN=Swagat, OU=Users, DC=rout, DC=Com. When an object can be defined uniquely, like in this example, it is called the distinguished name.
Canonical Name (CN):-

This is the name of the object in Active Directory that you want to access. For example, if you wanted to access a user called Joe, you would use CN=Swagat.
Organization Unit (OU):-

Organization units in Active Directory are used to sort objects into different areas or folders. If you have multiple OUs, then start with the lowest in the tree and expand downwards. For example if a user was in Users\Acounts\Payable you would use OU=Users, OU=Accounts, OU=Payable.
Domain Component (DC):-

This is the domain in which the object is located. For example DC=rout, DC=com

SYSVOL:-
It is a share directory,The domain uses for acess and replication throughout forest.
c:\windows\system32\%systemroot%\sysvol

NTDS.DIT:-

It stands for New Technology Directory services.The Active Directory Database by default is stored in c:\windows\NTDS\ntds.dit. This file is based on the X.500 standard. Originally Active Directory was called NT Directory Services and this is where the file got its name.Each domain in Active Directory will have a separate database. Domain Controllers hold the copy of the database in the ntds.dit file and replicate changes to each other. If you have more than one domain, then each separate domain will have its own copy of the ntds.dit file.

TREES:-
Tree is collection of Domains in a contigious manner.

FOREST:-
It is a collection of trees tha shares the common global catalog and schema master.

ORGANISATIONAL UNIT(OU):-
It is like a folder.All the objects are stored in organisational unit.OU is a container.We can give all the permissions here.
OBJECT:-
 All the hierichal information stored in Active Directory is called objects , 2 types of objects are there

• Container Object(It contain object)ex: OU

Leaf Object(It does not conatain any object)

                                      ACTIVE DIRECTORY STRUCTURE

2 types

•   Logical Structure                                     . Physical Structure

                             1. Domain                                             1. Domain Controller        

                             2. Trees                                                 2. Sites

                             3. Forest