In relational databases, what does the term "entity" refer to?

The term "entity" in the context of relational databases refers to a defined object that has a unique representation. Entities represent real-world objects or concepts that have significance within the database. For instance, in a hospital information system, entities could be patients, doctors, or treatments. Each entity is characterized by its attributes, which define the properties of the entity.

Entities are fundamental to the structure of a relational database as they help in organizing data into tables. Each table corresponds to an entity, with each row in the table representing a specific instance of that entity, identified by a unique key. This unique representation enables clear identification and differentiation between instances of the same entity type.

Understanding this concept is crucial for anyone working with database design and management as it lays the groundwork for how data is structured, stored, and accessed in a relational database environment.