Both are correct, but the second one, when multiplicity is set to more than one, is used more naturally, and it is not necessary to define the collection class as it is shown in the first picture of your example.
Simply said, multiplicity defines how many instances of a specific type can be stored by attribute. This set of instances can be ordered, or duplicates in it may be allowed. Parameters of multiplicity elements have an impact on the type of collection which should be used, Set, Vector, Array, etc.
But, if you need precise info about this issue, read UML Superstructure. Search for Property and Multiplicity Element. here is the UML website