Introduction to Data

Data: The Foundation of Decisions

Every day, people make choices based on data or information. When you pick a college for admission, you look at placement records from previous years, the qualifications and experience of faculty, the quality of labs and hostels, and the fees charged. The college you finally choose is identified through an analysis of all this data. Governments do the same thing on a much larger scale — they systematically collect and record population data through a process called a census. Census data holds valuable information that helps in planning and forming policies. A sports team's coaching staff studies past performances of opponent teams to build match strategies. Banks keep detailed records of customers, their account details, and every transaction. All these examples show one thing clearly: data is essential across every field. Data is what drives decision-making.

But raw data alone is not enough. In the college example, suppose the placement cell has records of 2,000 students placed in different companies at various salary packages over the last three years. Looking at that raw list of names, companies, and salaries tells you nothing useful. You cannot make any meaningful remark about the college's placement performance just by staring at the data. The college must process and analyse that data first. The results — summaries, averages, and visual charts — are what go into the placement brochure. Only then does the data become understandable and useful. So data must be gathered, processed, and analysed before it can support decisions.

What Exactly Is Data?

In general terms, data is a collection of characters, numbers, and other symbols that represent values of some situation or variable. The word "data" is plural; its singular form is "datum." When we use computers, data is stored in electronic form because electronic data processing is much faster and easier than manual processing done by people.

The Information and Communication Technology (ICT) revolution — driven by computers, mobile phones, and the Internet — has led to the generation of enormous volumes of data at an incredibly fast pace.

Common Examples of Data

We encounter data constantly in many forms:

• Personal details like name, age, gender, and contact information of a person
• Transaction data generated through banking, ticket booking, and shopping — whether done online or offline
• Media files such as images, graphics, animations, audio, and video
• Documents and web pages
• Online posts, comments, and messages
• Signals generated by sensors
• Satellite data, including meteorological data, communication data, and earth observation data