An Introduction to Database Management Systems
A database is a collection of related files that are usually integrated, linked or cross-referenced to one another. The advantage of a database is that data and records contained in different files can be easily organized and retrieved using specialized database management software called a database management system (DBMS) or database manager.
DBMS Fundamentals
A database management system is a set of software programs that allows users to create, edit and update data in database files, and store and retrieve data from those database files. Data in a database can be added, deleted, changed, sorted or searched all using a DBMS. If you were an employee in a large organization, the information about you would likely be stored in different files that are linked together. One file about you would pertain to your skills and abilities, another file to your income tax status, another to your home and office address and telephone number, and another to your annual performance ratings. By cross-referencing these files, someone could change a person's address in one file and it would automatically be reflected in all the other files. DBMSs are commonly used to manage: * Membership and subscription mailing lists * Accounting and bookkeeping information * The data obtained from scientific research * Customer information * Inventory information * Personal records * Library information
DBMSs and File Management Systems
Computerized file management systems (sometimes called file managers) are not considered true database management systems because files cannot be easily linked to each other. However, they can serve as useful data management functions by providing a system for storing information in files. For example, a file management system might be used to store a mailing list or a personal address book. When files need to be linked, a