Multiplicity
Multiplicity specifies the number of objects that are connected to one another.
You can specify the following multiplicities:
0..1 (number: either 0 or 1)
1 (number: 1)
* (number: 0 or any number)
1..* (number: 1 or any number)
Any values between the lower limit 0 and the upper limit *. You can also specify several ranges of values, for example, 1..2, 5..8, 11..13.