In database management, an entity is a real-world object or thing that has certain properties called attributes that define the nature of the entity. Examples of entities include a person, place, thing, or event. Entities can be categorized into two types: strong and weak. A strong entity is an entity that can exist independently of other entities, while a weak entity is an entity that depends on another entity for its existence.
Entities are distinguishable, meaning that each entity in a pair of entities has a property that makes one entity different from the other entity. For example, a black piece entity on a chessboard and a white piece on a chessboard are distinguishable since the color of the black piece and the white piece are distinguishable.
In database management systems, entities are used to represent real-world objects, while entity sets are a collection of entities of similar types. In relational models, each row in a table is a separate entity, while the whole table is an entity set.
Overall, entities are an important concept in database management systems as they help to organize and categorize information in a way that is useful for businesses and administrators.
