Or, how about an explanation and an analogy:
The explanation:
A dog is zero persons in one being.
A person is one person in one being.
God is three persons in one being.
The analogy:
One way to try to grasp the concept of the Trinity is to look at an egg. It has three component parts - shell, yolk, and white. In order to be an egg, it must have those three parts. While all 3 parts are “egg”, and can be used separately, they are best and most meaningful when together. (Yes, an egg has other parts, too, but they are all sub-components of shell, yolk, and white.) Eliminate one of the three and it is missing a necessary element. The part we see revealed to the world is the shell, which we can compare to Jesus - God presented to us in a way we can touch. The part hidden from us is the yolk which we can compare to God the Father, the procreative portion and origin of new life, dimly visible through the shell. The part inbetween, nearly invisible in to the eye, is the white, which can be compared to the Holy Spirit - we may not see it right away, but when the egg is opened we can easily feel it and observe its effects.
One of the points of the egg analogy is to illustrate the interdependence of our triune God. Jesus is fully God, but not all by His lonesome. Same with the Father and the Spirit. You can even ignore one or two of the three, just as you can imagine that the eggshell has no contents worth examining, or look only at the yolk and ignore the rest. The Father is still God, even to Jews and Muslims who don’t believe in Jesus, and vice-versa. But you have an incomplete picture unless you acknowledge all three together.
Hope this helps.
Nan