Strictly speaking, monasticism is a dedication to a fellow community based on the renunciation of worldly pursuits in order to devote oneself more fully to spiritual work. Traditionally, successful monastic orders have centered around various religious doctrines, most notably within the Christian and Buddhist faiths–though other examples exist throughout history. Community life is generally centered around a principle doctrine, and membership requires participation towards a certain telos* specific to that doctrine.
*Telos is broadly defined as a purpose, and it is classically demonstrated as follows: when describing a knife, one could name several properties of the knife–it is long, sharp, hard, cold, etc.–but at some point, one would also have to say that a knife is for cutting; cutting is the telos of the knife.
Many different kinds of monasticism exist in the world. For instance, Trappists–who follow strictly the Rule of St. Benedict–must work in order to sustain the monastery, and must not be dependent on external support. On the other hand, many Buddhist monks are forbidden from simple activities like growing and cooking food, or handling money, as a means of ensuring dependence on the lay community.
Many Christian orders differentiate between the eremitic (hermit) and cenobitic (community) orders, for example: while the eremitic orders seek seclusion and removal from worldly affairs, the cenobitic orders seek to ameliorate human suffering, and help spread the telos of the Church (union with Christ).
Generally, monasticism involves a strict observance of particular rules and conduct. Most monastic orders maintain strict standards for appearance, mannerism, time scheduling, and course of study, though some monastic order are far more liberal. Generally, a habit or robe is worn to symbolize membership in the order, and there is some kind of hierarchy (though not always).
Monasticism frequently involves set times for eating, sleeping, prayer/meditation, study, and work. Many Trappist orders are able to support their monastery financially with around four hours of dedicated work, six days a week (a total of twenty-four hours of work per week). In addition to this, they will work for two hours a day on personal project, with the rest of the day being dedicated to chores, prayer/meditation, study, eating, and sleeping. Buddhist monks frequently spend much of the day in meditation, and are encouraged to develop meditation skills even while doing chores. At night, they often attend an evening lecture, and have a few hours for personal study throughout the day. Lay supporters come to the monastery to do much of the work that monks are forbidden from doing, such as tending to the garden, cooking, etc., while the monastery is largely supported financially by donations.
Most monastic orders are cenobitic, and thus derive a lot of support from the communities in which they participate. Indeed, community support (not necessarily financial support) seems to play an essential part in the long-term success of cenobitic monasteries. Such monasteries often serve their communities by offering intellectual and moral support, spiritual guidance, and hospitality to those in need.