The word Trinity is used to describe one God - revealed through the entirety of scripture as three persons-Father, Son and Holy Spirit-three in one. Fully God, Fully Son, Fully Spirit - interacting in relationship within one God, and in relationship with humans in a way that leaves little room for full understanding outside of faith. God the creator, the Son begotten and the Spirit given.
One God - who always was, always is and will always be. Not created, but the Creator. Within one God, a Father, a Son and a Holy Spirit. A Father, who created everything. A son who became human, lived a perfect life, was crucified and rose again. A Holy Spirit who is gifted to those who believe-residing in them to guide through their conscious. All three present in one God-always.
We desire to put human understanding to what is not human. To pull from scripture certain verses that help us to describe what is seemingly undescribable. To attach relationship to and therefor give meaning, but in order to hold true to worship of One God - holding no idols - it is best to not try to put into complete understanding what is not meant to be understood. It is ok to not having some "it is like" statement to try to explain what we know to be true of the Trinity-the GodHead - three in one.
To my best understanding - God is one and three. There exists a relationship-revealing Father, Son and Spirit - but this relationship does not create three persons. Where the Father is, there is also the Son and the Spirit. They are one. When we worship, we worship God the Father, Son and Spirit. God is not an actor - playing three different roles - he mnipotent, omnipresent, eternal. "One in work and One in purpose."