A flat file database is the simplest type of computer database. It is like an electronic filing cabinet. The file folders in a filing cabinet are like the tables in a database. Building a database is an iterative process that involves gathering information, sifting through the information, adding tables, filing information, revising tables, and then gathering more information. The additional step in building a relational database is to link the tables and tie everything together. The information in Haz-Map was derived from textbooks, journal articles, web sites and CD-ROM flat file databases.