Final answer:
The number of links/associations among objects in an entity relationship diagram is called cardinality, which indicates the uniqueness of data values in a column and the type of relationship between entities.
Step-by-step explanation:
The number of links/associations that occur among objects in an entity relationship diagram is called cardinality. In the context of database design, cardinality refers to the uniqueness of data values that can be formatted in a column. Cardinality is a critical concept in database design, and is an aspect of the role keys play in a relational database. For example, if we have an entity called 'Student' and another entity called 'Class', the cardinality of their relationship could be one-to-many (1:N), which signifies that one student can enroll in multiple classes, but a class could have multiple students as well.