ABSTRACT
Databases A database is a collection of related files. How those files relate together and to each other depends almost entirely on the model that is used. One early database model includes the hierarchical model (as in Information Management System [IMS] databases), where all files and all records are and have to be related in a parent-child manner, similar to a single-parent household where each child has at most one parent at any given time, but where each parent can have multiple children. Another early model is the network model, with its files related as owners and members. This model resembles blended and extended families, where each owner (or each parent) can have multiple children (members) and each child can have multiple parents.
