Data, Information and the Need for a Database

Every business and every office runs on facts. The name of a customer, the price of a product, the quantity sold on a particular date, the roll number of a student, or the balance in a bank account — all of these are examples of data. In this Odisha CHSE (+2 Commerce) Information Technology course you will see that almost every computer application, from a shop's billing counter to a school's examination system, is really a tool for storing data and turning it into useful information.

Data are raw, unprocessed facts and figures that on their own may not carry a complete meaning. For example, the numbers 72, 85 and 64 are just data. When data are collected, organised and processed so that they become meaningful and useful for taking a decision, they become information. If we are told that 72, 85 and 64 are the marks scored by a student in three subjects and that the student's average is 73.6%, the same numbers now carry meaning — that is information. In short, information is processed data, and the whole purpose of storing data well is to be able to obtain useful information from it quickly and accurately.

A database is an organised collection of related data stored in such a way that it can be easily accessed, managed and updated. The word 'organised' is the key idea: the data are not scattered across loose sheets or unrelated files but are arranged in a structured form (most commonly in tables) so that a computer can search, sort and combine them efficiently. A telephone directory, a library catalogue, and a school's list of students with their classes and marks are all everyday examples of databases — collections of related facts kept together in a fixed structure.

Before databases became common, organisations stored data in ordinary computer files — one file for customer details, another for orders, another for payments — each handled directly by a separate program. This file-based approach worked for small amounts of data but created serious problems as the data grew. Solving those problems is exactly what a Database Management System is designed to do, as the next section explains.