Multiplicity vs Cardinality

Question

When talking about data models and databases, the term Cardinality is often used to describe the number of allowed elements in a given set.

UML oft

Answer 1

The simplest explanation would be to say:

Multiplicity = Cardinality + Participation

Cardinality: Denotes the maximum number of possible relationship occurrences in which a certain entity can participate in (in simple terms: at most).

Participation: Denotes if all or only some entity occurrences participate in a relationship (in simple terms: at least).

Ex: