Tattva is a Sanskrit word meaning 'thatness', 'principle', 'reality' or 'truth'. According to various Indian schools of philosophy, a tattva is an element or aspect of reality conceived as an aspect of deity. Although the number of tattvas varies depending on the philosophical school, together they are thought to form the basis of all our experience. The Samkhya philosophy uses a system of 25 tattvas, while Shaivism recognises 36 tattvas.
Read more about Tattva: Tattvas in Samkhya, Tattvas in Shaivism, Tattvas in Gaudiya Vaishnavism (i.e., The Philosophy Behind ISKCON), Tattva in Jainism, See Also