Introduction > Traditional Database Modeling > Definition
Information and data are different. Information is understood by a person. Data are values stored
on a passive medium like a computer disk. The purpose of a database management system (DBMS)
is to bridge the gap between information and data - the data stored in memory or on disk must be
converted to usable information.
The basic processes that are supported by a DBMS are:
- Specification of data types, structures and constraints to be considered in an application.
- Storing the data itself into persistent storage.
- Manipulation of the database.
- Querying the database to retrieve desired data.
- Updating the content of the database.
A database is a model of a real world system. The contents (sometimes called the extension) of
a database represent the state of what is being modeled. Changes in the database represent events
occurring in the environment that change the state of what is being modeled. It is appropriate to
structure a database to mirror what it is intended to model.
Databases can be analyzed at different levels:
- Conceptual Modeling.
- Logical Modeling.
- Physical Modeling.
