This document provides an overview of relational databases. It defines a relational database as one that stores and provides access to data points that are related to one another. The data is stored in tables that contain rows and columns, with each row representing a record and each column representing a field or attribute. Key terms are also defined, such as tables, records, fields, columns, and NULL values. Advantages of relational databases include ease of use, flexibility, precision, security, and data independence. Disadvantages include potential performance issues and slower data extraction for hierarchical data.