Q.Fill in the blank : In a relational model, tables are called _________, that store data for different columns.

Database Fundamentals

Think of a database as a well-organised filing cabinet. In your daily life, you already manage small databases without realising it — your phone's contact list, the catalogue of a library, or even the list of students in a class register. Each of these is a collection of related information stored in a structured way so that you can find what you need quickly.

What Exactly Is a Database?

A database is a collection of related data that is stored and managed systematically. The key word here is related. A random pile of papers on a desk is not a database — but the same papers, sorted into folders with labels and a clear order, become one. The purpose of a database is to allow efficient storage, retrieval, modification, and deletion of data.

Why Do We Need Databases?

Imagine a small business that keeps customer orders in a notebook. As the business grows, the notebook becomes impossible to manage — pages get lost, two customers might be given the same order number, and finding a specific order takes forever. A database solves all these problems.

Databases provide:

• Centralised control — all data lives in one place, so everyone works with the same information
• Data consistency — rules can be enforced (for example, an order must belong to a real customer)
• Security — different users can be given different levels of access
• Reduced redundancy — the same piece of information is not stored in multiple places unnecessarily
• Data independence — the way data is stored can change without affecting how users view it

The Core Idea: Tables and Relationships

The most common type of database is the relational database. Think of it as a collection of tables, where each table stores information about one kind of thing.

A table is made up of rows and columns. Each column represents a field (a single piece of information, like a name or a date), and each row represents a record (one complete set of fields, like one customer's full details).

For example, a university might have a Student table with columns: Roll Number, Name, Date of Birth, and Course. Each row is one student.

The real power comes from relationships between tables. The same university might have a Course table and an Enrolment table. The Enrolment table links a student to a course using the student's roll number and the course code — without repeating all the student's details or all the course details. This is what makes a database efficient.

Database Management System (DBMS)

A Database Management System is the software that lets you create, manage, and interact with a database. You do not directly touch the data files — the DBMS does that for you. Popular examples include MySQL, Oracle, and Microsoft Access.

The DBMS handles:

• Data storage and retrieval — it decides how to physically store data on a disk
• Query processing — when you ask for "all students born after 2005", the DBMS finds the answer …