Introduction to Databases

A database is an organized collection of data that can be easily accessed, managed, and updated. Instead of storing information in scattered files, a database keeps it structured so applications and users can reliably read and write it.

Why Databases Matter

• Store large volumes of data efficiently and reliably
• Allow multiple users and applications to access data simultaneously
• Enforce rules that keep data accurate and consistent
• Support fast searching, filtering, and reporting

Types of Databases

• Relational databases (RDBMS) - store data in tables with rows and columns, e.g. MySQL, PostgreSQL, SQL Server
• NoSQL databases - store data in flexible formats like documents or key-value pairs, e.g. MongoDB, Redis

A Simple Database Concept

Think of a spreadsheet: rows represent individual records (like customers), and columns represent attributes of those records (like name, email, and city). A relational database formalizes this idea with rules and a query language to manage it at scale.