This document provides an overview of key concepts in the study of religion. It defines religion and explores reasons for its existence, including helping humans cope with mortality and find meaning. The major world religions are identified as Christianity, Islam, Hinduism, Buddhism, and Judaism. Seven key elements of religions are outlined: doctrine, mythology, religious experiences, institutions, ethical content, rituals, and sacred objects/places. Examples are given for each element. The document suggests religion is a universal human activity that addresses existential questions through various practices and traditions.