Don't forget everyone, the Trinity is perhaps more than anything a mystery. Actually, it is THE Mystery. Really, we can only know to the point, thanks to His great mercy, that God chooses to reveal Himself too us. There are a few things we can say about the Trinity, quoted from the Catechism of the Catholic Church (CCC):
253: The Trinity is One. We do not confess three Gods, but one God in three persons, the "consubstantial Trinity." The divine persons do not share the one divinity among themselves but each of them is God whole and entie: "The Father is that which the Son is, the Son that which the Father is, the Father and the Son that which the Holy Spirit is, i.e. by nature on God."
254: The divine person are really distinct from one another. "God is one but not solitary." "Father," Son," "Holy Spirit" are not simply names designating modalities of the divine being, for they are really distinct form one another: "He is not the Father who is the Son, nor is the Son he who is the Father, nor is the Holy Spirit he who is the Father or the Son." Thay are distinct form one another in their relations of origin: "It is the Father who generates, the Son who is begotten, and the Holy Spirit who proceeds." The divine Unity is Triune.
255: The divine persons are related to one another. Because it does not divide the divein unity, the real distinction of the persons from one another resides solely in the relationships which relate them to one another: "In the relational names of the persons the Father is related to the Son, the Son to the Father, and the Holy Spirit to both. While they are called three persons in view of their rlations, we believe in one nature or substance." Indeed "everything (in them) is one where there is no opposition of relationship: "Because of that unity the Father is wholly in the Son and wholly in the Holy Spirit; the Son is wholly in the Father and wholly in the Holy Spirit; the Holy Spirit is wholly in the Father and wholly in the Son.: