Dictionaries define "Judaism" as The monotheistic religion of
the Jews, since the founding principle of Judaism was and is
the belief in One God. This was the teaching which was spread by
Abraham, and has continued since then.
God is One. The concept of a dualism (as in Zoroastrianism), an independent Satan, multiple gods (polytheism; paganism) or a trinity of three in one, are all unimaginable in Judaism. Also, any belief that an intermediary between humanity and God should be used, whether as necessary or even optional, is considered heretical.God is non-physical, indivisible and incomparable.
Jews practice Monotheism (only one God). Most Christian denominations practice Trinitarianism (three gods in one) and some Christian denominations believe in Tritheism (three distinct and separate gods).
Christianity and Judaism are two of the three great monotheistic religions, the third being Islam.
No Christian denomination practices Trinitarianism in the sense stated in the answer above for no Christian believes in more than one God or god. All Christians believe in only one God or they would not be Christian.
All Christian churches believe in the doctrine of the trinity as stated in the Apostles, Nicene, and particularly the Athanasian creeds.
Note that in the text of the Athanasian creed the word Catholic means Christian, not Roman Catholic as it means today. In other words, the Athanasian creed was a statement of Christian doctrine, to combat a number of errors which arose at that time, particularly Arianism, which taught that Jesus was not God.