TYPES OF DATABASES / DATABASE TYPES / DBMS BASICS

A data base is a collection of logically related data stored in a standardized format and is sharable by multiple users. The different database types are:
1. Centralized database
2. Operational database
3. End-user database
4. Commercial database
5. Personal database
6. Distributed database
Centralized database: Users from different locations can access this database from a remote location at the central database, that store entire information and application programs at a central computing facility for processing. The application programs pick up the appropriate data from the database based on the transactions sent by the communications controller for processing the transaction.
Data validation and verification is carried out by the application programs at the central computer centre, and a registration number is allotted by the application programs located at the central facility. The local area office keeps on recording it and hardly does any processing.
Operational database: This is more of a basic form of data that contain information relating to the operations of an enterprise. Generally, such databases are organized on functional lines such as marketing, production, employees, etc.
End user database: End user is the user of software, application or a product. This is a shared database which is shared by users and is meant for use by the end users, just like managers at different levels. They may not be concerned about the individual transactions as found in operational databases. This database is more about the summary of the information.
Commercial database: This is a database that contains information which external users may require. However, they will not be able to afford maintaining such huge database by them. It’s a paid service to the user as the databases are subject specific. The access to commercial database can be given through commercial links.
Personal database: The personal databases are maintained, generally, on personal computers. They contain information that is meant for use only among a limited number of users, generally working in the same department.
Distributed database: These databases have contributions from the common databases as well as the data captured from the local operations. The data remains distributed at various sites in the organization. As the sites are linked to each other with the help of communication links, the entire collection of data at all the sites constitutes the logical database of the organization