The Trinity is the teaching of one God in three persons: Father, Son, and Holy Spirit. Each is distinct from the other, but each is divine and of one substance. They are all the one God, not three gods. A triad is three separate gods. The biblical Trinity is not a triad.
The Jehovah’s Witnesses deny the Trinity and repeatedly misrepresent it by saying it is a triad of three gods. The Mormons also deny the Trinity and teach a triad of Gods: a God called Elohim who is supposed to be the Father. They teach that Jesus is another God and that the Holy Ghost is a third god. In Mormonism, the three comprise the Godhead of three separate gods.
So, the proper and true doctrine of the Bible and Christianity is that the Trinity is one God in three persons, not a triad of three separate gods.