Final answer:
A many-to-many relationship with an associative entity in a database is referred to as a Many-to-Many relationship. An additional table, often called a junction table or associative entity, is used to manage this type of relationship.
Step-by-step explanation:
The type of database relationship that involves a many-to-many relationship with an associative entity is known as a Many-to-Many relationship. In a Many-to-Many relationship, a record in one table can relate to many records in another table, and vice versa. To manage this kind of relationship, an additional table is used, commonly called a junction table or an associative entity, which holds foreign keys that reference the primary key on each of the related tables.
This associative entity is essential because it uniquely identifies the combination of associated records from the two tables and can also store additional attributes relevant to the relationship. For example, consider a database for a book club application where one table holds members and another holds books. A member can check out multiple books, and each book can be checked out by multiple members. The associative entity, which could be named 'Checkouts', tracks each unique combination of book and member checkouts, along with details such as the checkout date and due date.