As of the early 21st century, Christianity has approximately 2.4 billion adherents, out of about 7.2 billion people. The faith represents approximately one-third of the world's population and is the largest religion in the world, with the three largest groups of Christians being the Catholic Church, Protestantism, and the Eastern Orthodox Church. The largest Christian denomination is the Catholic Church, with 1.09 billion adherents. The second largest Christian branch is either Protestantism (if it is considered a single group), or the Eastern Orthodox Church (if Protestants are considered to be divided into multiple denominations).