Entity Sets:-An entity is a “thing” or “object” in the real world that is distinguishable from all
other objects. For example, each person in an enterprise is an entity. An entity has a
set of properties, and the values for some set of properties may uniquely identify an entity.
An entity set is a set of entities of the same type that share the same properties, or
attributes.The set of all persons who are customers at a given bank, for example, can be defined as the entity set customer.The individual entities that constitute a
set are said to be the extension of the entity set.Entity sets do not need to be disjoint.
A database thus includes a collection of entity sets, each of which contains any
number of entities of the same type.
other objects. For example, each person in an enterprise is an entity. An entity has a
set of properties, and the values for some set of properties may uniquely identify an entity.
An entity set is a set of entities of the same type that share the same properties, or
attributes.The set of all persons who are customers at a given bank, for example, can be defined as the entity set customer.The individual entities that constitute a
set are said to be the extension of the entity set.Entity sets do not need to be disjoint.
A database thus includes a collection of entity sets, each of which contains any
number of entities of the same type.
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