Linux System Calls Question:

NIS is a service that provides any user on that network
with the same working environment irrespective of the
system on that network which has been used for login
purpose.
For example if NIS server is set up in a single system and
configured to hold user accounts and their passwords and
access information. Then any user on that network can login
to his/her account that is set up in the NIS server from
any system (with nis client running) on that configured
network. This gives a look and feel that the user is logged
into his/her own system. But actually its the account on
the NIS server that is mounted on the local sytem on user
login .