Relationships allow to define the equivalence and difference between Classes.
One can for instance state that two Individuals are the same.
On the other hand one can also state the difference of two Individuals and one has to do that, because of the Open World Asssumption it is always possible that two Individuals are proabably the same. So one can denote
owl:differentFrom which states that two individuals are not the same. Sometimes one as sets of Individuals and one wants to sate that all of them a different from each other. For this there is a shortcut so one does not need to state the difference between each single pair of Set.
One can define a Set and state that all members are all different from each other. One does this via the
owl:AllDifferent Class and one defines some nodes as being belong to this Class and one states that the members of this Class are a RDF Collection. and there one states that all the Individuals that are in this Collection are really different from each other.
:EVA a :AI ; :isMadeOf :Intelligence ; :hasBuildingYear 2013 ; owl:sameAs :ElectronicVideoAgent . :AI a owl:Class ; rdfs:subClassOf :Program . :Program a owl:Class .
Difference of Individuals via
:ElectronicVideoAgent a :AI ; owl:differentFrom :ElectronicVideoAssistent .
OWL provides a shortcut to define several Individuals to be different
 a owl:AllDifferent ; owl:distinctMembers (:Hevok :EVA :Cabal) .