In an ER diagram, what does a line between two entities denote?

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Multiple Choice

In an ER diagram, what does a line between two entities denote?

In an ER diagram, a line between two entities shows a relationship between them. It signals that instances of one entity are connected to instances of the other, such as a customer placing orders. The line can have cardinality indicators (one-to-one, one-to-many, many-to-many) that describe how many instances relate. It's not about data flow, discarded objects, or directly showing how keys connect; the line communicates the existence of a linkage, while in a relational design the actual key-based link is implemented via foreign keys in tables. For example, a Customer–Order line represents that a customer can be associated with multiple orders.

In an ER diagram, a line between two entities shows a relationship between them. It signals that instances of one entity are connected to instances of the other, such as a customer placing orders. The line can have cardinality indicators (one-to-one, one-to-many, many-to-many) that describe how many instances relate. It's not about data flow, discarded objects, or directly showing how keys connect; the line communicates the existence of a linkage, while in a relational design the actual key-based link is implemented via foreign keys in tables. For example, a Customer–Order line represents that a customer can be associated with multiple orders.

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