Each table stores a different type of information. For instance, the Hosts table stores host name/Internet address pairs, and the Password table stores information about users of the network.
NIS+ tables have two major improvements over NIS maps. First, a NIS+ table can be accessed by any column, not just the first column, which is sometimes referred to as the “key.” This access eliminates the need for duplicate maps, such as the hosts.byname and hosts.byaddr maps of NIS. Second, access to the information in NIS+ tables can be controlled at three levels of granularity: the table level, the entry level, and the column level.