Professional fraternities are often confused with honor societies because of their focus on a specific discipline. Professional fraternities are actually significantly different from honor societies in that honor societies are associations designed to provide recognition of the past achievement of those who are invited to membership. Honor society membership, in most cases, requires no period of pledging, and new candidates may be immediately inducted into membership after meeting predetermined academic criteria and paying a one-time membership fee. Because of their purpose of recognition, most honor societies will have much higher academic achievement requirements for membership.