When you install the operating system, you supply the host name and IP address of your server, clients, or standalone system as part of the procedure. The Solaris installation program enters this information into the hosts and ipnodes network databases. These databases are part of a set of network databases that contain information necessary for TCP/IP operation on your network. The name service that you select for your network reads these databases.
The configuration of the network databases is a critical. Therefore, you need to decide which name service to use as part of the network planning process. Moreover, the decision to use name services also affects whether you organize your network into an administrative domain. Network Databases and nsswitch.conf File has detailed information on the set of network databases.