What are relational databases?

A relational database is a type of database that uses a tabular structure to store and organize data.

Key features:

• Tables: Data is stored in tables consisting of rows (records) and columns (fields).
• Schemas: Define the structure of tables, data types for columns, constraints (e.g., uniqueness).
• Keys:
  • Primary Key: Uniquely identifies each row in a table.
  • Foreign Key: Establishes a relationship between tables by referencing the primary key of another table.
• Relationships: Define links between tables based on foreign keys (one-to-one, one-to-many, many-to-many).
• SQL (Structured Query Language): The standard language for interacting with relational databases - querying, modifying, and managing data.
• Normalization: The process of organizing columns and tables to reduce data redundancy and improve data integrity.

Examples of relational DBMS: MySQL, PostgreSQL, Oracle Database, Microsoft SQL Server.