Question: what are the three categories of the essential buddhist way of life?
Answer: In Buddhism, the three marks of existence are three characteristics (Pali: tilakkhaṇa; Sanskrit: त्रिलक्षण, trilakṣaṇa) of all existence and beings, namely impermanence (aniccā), unsatisfactoriness or suffering (duḥkha), and non-self (anattā).