Relational databases are a type of software used to store and manage data in a structured manner. They are based on the relational model, which organizes data into tables with rows and columns. Each table represents a specific entity or concept, and the columns represent the attributes or characteristics of that entity. The relationships between tables are defined by keys, which link the data together. Relational databases are widely used in business and other applications to store and manage large amounts of data efficiently and securely. They are also highly scalable, allowing organizations to easily add or remove data as needed.