Presbyterianism, whose bodies are also called Reformed Churches, share a common origin in the 16th-century Swiss Reformation and the teachings of John Calvin, and today is one of the largest Christian denominations in Protestantism.
There are about 75 million Reformed or Presbyterian Christians worldwide; about 2.5 million belong to the Presbyterian Church (U.S.A.).
The name "Presbyterian" comes from the representational form of church government called presbyterian. In presbyterian churches, governing authority is given to elected lay leaders known as "elders" (or "presbyters"), who work with the congregation's ordained minister. Presbyterian belief and practice center on the Bible and the sovereignty of God.