So this says that it's impossible, by definition, to measure exactly the state -- i.e., the position -- and the momentum of a particle, because the act of measuring it, by definition, changes it.
On nam govori kako je nemoguće, po definiciji, mjeriti točno stanje, npr. poziciju, i impuls čestice, jer čin mjerenja, po definiciji, mijenja česticu.