  We define equivalence relations for both sequences of point blow-ups of
smooth d-dimensional projective varieties and for associated sequential
morphisms and we prove that there exists a bijection between the respective
equivalence classes of sequences of point blow-ups and the associated
sequential morphisms. Moreover we show some diferences when dealing with the
more general case of sequences of blow-ups of smooth 3-dimensional projective
varieties, where all possible dimensions for the centers are allowed.
