A relational database stores data in structured tables with rows and columns, enforcing relationships through primary and foreign keys. It uses the SQL language for querying, updating, and managing data. Relational databases offer ACID transactions, strong consistency, and robust indexing.
Why it matters
Relational databases are ideal for structured, highly consistent data such as financial transactions, inventory systems, and user management. Their mature tooling and predictable behavior make them foundational to modern applications.
Examples
MySQL, PostgreSQL, and MariaDB are popular relational databases. Lessons like SQL vs NoSQL Databases compare relational and non-relational systems.