Various organizations must track information about people, clients, events, finance, goods, etc. Managing this information is crucial. A database allows us to manage and use a variety of information easily. Databases allow us to maintain order in what could be a very chaotic environment.

First, we consider the characteristics of databases and describe the most important database applications. We summarize the history of database processing. At the end, we give description of various database components and provide a survey of knowledge about database systems.