Credo: I Believe.
Creed: 1. a brief authoritative formula of religious belief. 2. a set of fundamental beliefs. ~ Merriam Webster. (https://www.merriam-webster.com/dictionary/creed)
A Creed is a statement of what someone believes, that is, the things one believes that make a difference in how they live their lives.
There are three historic ecumenical creeds in the Christian church. Ecumenical means accepted by many different churches. These three creeds are: 1) The Apostles' Creed. 2) The Nicene Creed and 3) The Athanasian Creed.
The Apostles' Creed is based on the Old Roman Creed (an early form of baptismal instruction). According to an ancient tradition, each of the twelve articles of faith in the Apostles' Creed was contributed by one of the twelve original apostles.
The Nicene Creed is an agreed statement of faith that the churches agreed upon at the Ecumenical Council of Nicaea in 325.
The Athanasian Creed, whose origins are uncertain, has been commonly used in Western Christianity. It contains a more detailed affirmation of faith in the Holy Trinity and the Divine and Human Natures of Christ. Authorship was traditionally ascribed to St. Athanasius.