Trinity -- Introduction
The historic teaching of the Church is that there is one God who exists in three Persons -- the Father, the Son, and the Holy Spirit. This teaching has come to be called the Trinity doctrine.

Shortly after the New Testament was completed, some began to think that it made more sense to believe that the Father, the Son, and the Holy Spirit are really three manifestations of the same Person appearing in different modes. This doctrine has come to be called Modalism. In the last century, a modern form of Modalism is often called the 'Oneness' or 'Jesus only' doctrine.

.....CONTD on https://christjesuscrucified./?s=trinity

Original source is http://www.biblicalcatholic.com/apologetics/a63.htm

How can God be the creator and also be part of creation.. Its like saying Steve Jobs, iPhone charger and iPhone battery are one... Those it make any sense?

The creator is outside of creation... He is not affected or constraint by time and space.