What is a Database?
A
database is a collection of permanently stored data used by an
application or enterprise.
A database contains
logically related data, which means that the
database was created with a purpose in mind. A database supports
shared access
by many users.
One characteristic of a database is that
many people use it, often for many different purposes.
A database is
protected to control access and managed to retain its value and integrity.
One example of a database is payroll data that includes the names of the
employees, their employee numbers, and their salary history. This
database is logically related—it's all about payroll. It must have shared
access, since it will be used by the payroll department to generate checks,
and also by management to make decisions. This database must be
protected; much of the information is confidential and managed to ensure
the accuracy of the records.
The
Relational Model is a set of principles for relational databases,
formalized by Dr. E.F. Codd in the late 1960s. The relational model of data
prescribes how the data should be represented in terms of structure,
integrity, and manipulation. The rules of the relational model are widely
accepted in the information technology industry, though actual
implementations may vary.
In Simple,
Database—A collection of permanently stored data that is:
–
Logically related—data relates to other data.
–
Shared—many users may access data.
–
Protected—access to data is controlled.
–
Managed—data has integrity and value.– Based on the relational model.