Most religions are practiced in fairly specific world regions. The spread of religions occurred mainly due to human migration and the development of telecommunications. This chart shows the percentage of the world's population that adheres to several of the major world religions. About one-third of the world’s population adheres to a form of Christianity. Latin America has the largest number of Christians, most of whom are Roman Catholics. Islam is practiced by over one-fifth of the world’s population, most of whom live in parts of Asia, particularly the Middle East.