Putting my thought in completely original way.
I work for a reputed Product Development Company. In My Village, Bhatotar, District Purnia, Bihar, I have an Identity. Many People haven’t seen me, But they know my identity ---
in IAM terms, They know my DN: cn=Ashish Kumar,OU=Bhatotar,OU=Purnia,OU=Bihar,C=in
with Following attributes
DN: cn=Ashish Kumar,OU=Bhatotar,OU=Purnia,OU=Bihar,C=in
University: VTU Belgaum
FatherName: cn=Dr. S C Jha,OU=Bhatotar,OU=Purnia,OU=Bihar,C=in
Here Age, Sex etc are normal attribute, and FatherName is a reference attribute. Again Father will have similar attributes. So here comes the hierarchy.
Again, On Some of the attributes of cn=Ashish Kumar, A group Named FamilynFriends (This Group Was created by GOD with initially having Family members only, but later, Ashish Kumar Added some more Users to this group) will have different rights than the public. Any Public can just read my salary (For Example) but will not have access to that, and they can't modify (Increase or Decrease) that.
Similarly, I have a Bike, Which has a unique Identity in the world.
Dn: cn=KA 01-9971,ou=RTO-1,ou=bangalore,ou=karnataka,c=In
owner: cn=Ashish Kumar,OU=Bhatotar,OU=Purnia,OU=Bihar,C=in
Model: Bajaj Pulser
[ACL]: [All Rights][cn=Ashish Kumar]
So, every living/nonliving thing is an identity, what I mean is nothing fancy, But It has name, some properties and relationship to some other things. The things can be Human, Bikes, Village, Nation, Mountains, Computers, Software, patches, Companies. Every thing has an Identity and Has Some Attributes and Have some Relation to other Identity.
Some Identities (Say person) owns some things (Say Bike), and has rights to that, It means there are system (Police/RTO) who will not allow others to use My Bike. So there is a management system (Local Administrator is Police, But Main LDAP Server Runs in Heaven and GOD is the Directory Administrator, And Has ultimate rights over any identity, He can Add/Modify/Delete/Search any Identity anytime)
So world is an organization, and we all are employees of that. We work for our family and friends here 24/7. Our Identities are secured. God Has Delegated Few Rights to Others on Some other Identities.
To Summarize, In Any Organization (Private or Govt), There has to be Identities and A hierarchy to manage them. There will be security policy and Access rights assigned to some Identity over other identity. Put all together, in software, which will provide an easy interface to manage these all, is Identity and Security management Software.