=====Overview=====
Oracle Unified Directory is a product of oracle which provides identity management. Identity management consists of three areas:

  - Directory Services
     * Storing User Identity
     * Providing User Information
  - Identity Governance
     * Providing Resources to users based on roles
     * Password management
     * Identity Analytics
  - Access Management
     * Determining who a user is: Authentication
     * Determining to what the user has access to: Authorization

Let's go through each of the areas first.

=====Directory Services=====
Oracle has mainly two Directory Services:

  - Oracle Internet Directory (OID)
  - Oracle Unified Directory (OUD)

Oracle Unified directory is the newer product and it is recommended by Oracle as it contains all the features. Oracle Internet directory can also provide directory services and as it is still used, Oracle will continue to support it.
Let's discuss each of them:

====Oracle Internet Directory====

====Oracle Unified Directory====
Oracle unified directory has several components:

  * Directory Server
  * Proxy Server
  * Replication Server
  * Replication Gateway

The term "unified" is used because Oracle Unified Directory, "unify" the following features.

  * Storage
  * Virtual
  * Sync
  * Proxy

Furthermore, OUD can be integrated with:
  * ODSEE 11g
  * FMW Control
  * EM Grid & EM Cloud Control
  * DIP Integration



However, let us see what are their differences:

====Differences====
Oracle internet directory is:

  * Using External Oracle Database (RDBMS)
  * Has Vertical Scalability
  * Supports only Oracle Centralized DB
  * Is Part Java / Part C

On the other side, Oracle Unified Directory:

  * Maintains data using embedded Barkley database
  * Provides Horizontal and Vertical scalability
  * Supports Distributed data
  * Is all in Java