What is DBMS?

A Database Management System (DBMS) is software that stores, retrieves, and manages data in a structured way. Examples: MySQL, Oracle, PostgreSQL, MS SQL Server.

Advantages over File System

• Reduces data redundancy
• Data integrity and consistency
• Multi-user access and concurrency control
• Backup and recovery
• Data security

Types of Databases

• Relational: Tables with rows and columns (SQL).
• NoSQL: MongoDB, Redis — flexible schema.
• Hierarchical: Tree structure (e.g. IBM IMS).
• Network: More complex relationships than hierarchical.