What entity type is created by many to many relationships?

A junction entity is used to manage many-to-many relationships between two other entities in a data model. When two entities have a many-to-many association, a junction entity serves as an intermediary, creating a unique record that links instances of each of the original entities.

For example, consider a scenario involving students and courses. Each student can enroll in multiple courses, and each course can have multiple students. To effectively manage this relationship, a junction entity, often referred to as an association or mapping entity, is created. This junction entity would include foreign keys from both the Student and Course entities, allowing the system to link students to the courses they are enrolled in.

The other types of entities listed do not serve this specific purpose. An extension entity is typically used to extend the attributes of an existing entity. A base entity is the foundational structure for data, often corresponding to a single table without complex relationships. A dynamic entity is used for scenarios where the schema might change at runtime, often serving more flexible or variable data types. Therefore, a junction entity distinctively fulfills the role of managing many-to-many relationships effectively.