The practices usually vary in different sub-schools and monasteries within Theravāda. But in the most orthodox forest monastery, the monk usually models his practice and lifestyle on that of the Buddha and his first generation of disciples by living close to nature in forest, mountains and caves. Forest monasteries still keep alive the ancient traditions through following the Buddhist monastic code of discipline in all its detail and developing meditation in secluded forests.
In a typical daily routine at the monastery during the 3 month vassa period, the monk will wake up before dawn and will begin the day with group chanting and meditation. At dawn the monks will go out to surrounding villages bare-footed on alms-round and will have the only meal of the day before noon by eating from the bowl by hand. Most of the time is spent on Dhamma study and meditation. Sometimes the abbot or a senior monk will give a Dhamma talk to the visitors. Laity who stay at the monastery will have to abide by the traditional eight Buddhist precepts.
The life of the monk or nun in a community is much more complex than the life of the forest monk. In the Buddhist society of Sri Lanka, most monks spend hours every day in taking care of the needs of lay people such as preaching bana, accepting alms, officiating funerals, teaching dhamma to adults and children in addition to providing social services to the community.
After the end of the Vassa period, many of the monks will go out far away from the monastery to find a remote place (usually in the forest) where they can hang their umbrella tents and where it is suitable for the work of self-development. When they go wandering, they walk barefoot, and go wherever they feel inclined. Only those requisites which are necessary will be carried along. These generally consist of the bowl, the three robes, a bathing cloth, an umbrella tent, a mosquito net, a kettle of water, a water filter, razor, sandals, some small candles, and a candle lantern.
The monks do not fix their times for walking and sitting meditation, for as soon as they are free they just start doing it; nor do they determine for how long they will go on to meditate. Some of them sometimes walk from dusk to dawn whereas at other times they may walk from between two and seven hours. Some may decide to fast for days or stay at dangerous places where ferocious animals live in order to aid their meditation.
Those monks who have been able to achieve a high level of attainment will be able to guide the junior monks and lay Buddhists toward the four degrees of spiritual attainment.
In Pali the word for a male lay devotee is Upasaka. Upasika is its female equivalent. One of the duties of the lay followers, as taught by the Buddha, is to look after the needs of the monk/nuns. They are to see that the monk/nuns do not suffer from lack of the four requisites: food, clothing, shelter and medicine. As neither monks nor nuns are allowed to have an occupation, they depend entirely on the laity for their sustenance. In return for this charity, they are expected to lead exemplary lives.
In Myanmar and Thailand, the monastery was and is still regarded as a seat of learning. In fact today about half of the primary schools in Thailand are located in monasteries. Religious rituals and ceremonies held in a monastery are always accompanied by social activities. In times of crisis, it is to the monks that people bring their problems for counsel.
Traditionally, a ranking monk will deliver a sermon four times a month: when the moon waxes and wanes and the day before the new and full moons. The laity also have a chance to learn meditation from the monks during these times.
It is also possible for a lay disciple to become enlightened. As Bhikkhu Bodhi notes, "The Suttas and commentaries do record a few cases of lay disciples attaining the final goal of Nirvana. However, such disciples either attain Arahantship on the brink of death or enter the monastic order soon after their attainment. They do not continue to dwell at home as Arahant householders, for dwelling at home is incompatible with the state of one who has severed all craving."