Database

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A Database is a repository for collection of related data or facts. A database contains a collection of related items or facts arranged in a specific structure. The most obvious example of a non computerized database is a telephone directory. Telephone companies now use an electronic database program to produce their printed phone books. Sometimes, we see a specialized phone book that is sorted not only by last name, but by other items such as phone number or street address. These books are easy to produce because the telephone company's electronic database can sort and organize the data in many different ways. Database programs can also sort lists of data, arranging them in alphabetical, numeric, or chronological order and can search or query data with different conditions.

Features of Database 

The data in a database should have following features

• Shared : Data in a database is sharing among different user and application.
• Validity : Data should be correct with respect.
• Security : Data should be protected from unauthorized user access.
• Non-redundancy : No two data items in a database should represent the same real word entity.
• Consistency : Data in a database should be same for all users.