The festival that celebrates the Buddha's birthday is known as Vesak or Buddha Purnima. This important event is observed in various countries, including India, Sri Lanka, and Thailand, usually occurring in April or May. Vesak commemorates not only the birth of Siddhartha Gautama, who became the Buddha, but also his enlightenment and passing into Nirvana. Celebrations include visiting temples, offering prayers and food to monks, meditating, and engaging in acts of kindness and compassion, reflecting the Buddha's teachings.