Entity

What is an Entity?

Entity refers to an “actual item” or “thing”.

In Simple Terms

An entity is essentially a “real thing”. For example, in an E-R diagram (Entity-Relationship diagram), an “entity” is represented by a “box”. This box represents a real-world item or concept within the context of a database.

In Detail

  1. Actual Item (Entity):
    • An “entity” represents a tangible or conceptual item that exists within a system. In database design, an entity refers to any object or concept that can have data stored about it.
    • Example: Customer, Order, Product—these are entities in a database.
  2. Entity in E-R Diagrams:
    • E-R diagrams are visual tools used to represent the structure of a database. In these diagrams, entities are shown as “boxes” that are connected by lines to represent relationships between them.
  3. Entities in Java:
    • In Java, particularly in the context of EJB (Enterprise JavaBeans), “entity” may refer to a different concept related to object persistence. However, in most contexts, it aligns with the idea of a tangible item or concept.

In Summary

When you encounter the term “entity”, think of it as referring to an “actual item” or “thing”.