Data can be in many collected and stored in many forms including text, graphics, and even audio and video formats. A properly designed database allows everyone that is authorized to access the data while allowing only certain individuals to modify the data. In this way, a database can provide instant reporting with a minimal amount of redundant data.
Databases are very similar to filing cabinets.
They contain many files or tables of data. After the data has been entered into the table, it can be queried for reporting purposes. A query is a way of selecting certain data from a table or a series of tables. Three types of database structures have evolved through the years. The Hierarchical Model was developed in the 1960's followed by the Network Model in the 1970's.