There are a few different types of holy orders in the world. There are monastic orders, religious orders, and apostolic orders. Monastic orders are orders of monks who live according to a stricter code of conduct and who are often focused on prayer and contemplation. Religious orders are orders of nuns who live according to a stricter code of conduct and who are often focused on service to others. Apostolic orders are orders of priests who have been chosen by the bishop or pope and are given special authority to minister to the laity.