ADAM, Active Directory, LDAP, ADFS, Identity
What is the difference/relation between ADAM, Active Directory, LDAP, ADFS, Windows Identity, cardspace and which server (Windows 2003, Windows 2008) uses what?
Answer
Active Directory is a server component for administrating windows domains and storing related informations like details about users. It provides implementations of the network protocols LDAP, DNS, CIFS and Kerberos. It's part of Windows Server 2003 as well as Windows Server 2008 with some modifications in the latter case.
ADAM was somewhat like the little brother of Active Directory. It only contained an implementation of LDAP. With Windows Server 2008 it was renamed to LDS, Lightweight Directory Services. ADAM/LDS can also be installed on non-server versions of Windows.
LDAP is a protocol for administrating the data of a directory service. Data within a directory services are stored in a hierarchical manner, a tree. Entries within that tree can contain a set of attributes where each has a name and a value. They are mostly used for storing user related informations like usernames, passwords, email addresses and so on, as there are standardized schemas for this purpose and it's widely supported by applications.
ADFS is a technology which enables Single Sign-On for users of web applications within an Identity Federation. In a very short form: Imagine two organizations which have their user data stored within an active directory. Now each organization wants to give the users of the other organization access to its web applications, but with the restriction that the user data itself should neither be copied nor be fully accessible to the other organization. Thats the kind of problem ADFS can solve. May require an hour of reading & researching before fully understood.