The five (pancha) themes of a Purana
Sarga
Creation and the life of Brahma.
Pratisarga
The secondary creation, beginning with the day of Brahma, ending with the night of Brahma, beginning again with the day of Brahma.
Manvantantara
The cosmic cycle.
Vamsa
Dynasties, beginning with lunar and sun dynasty (Chandra Vamsa and Surya Vamsa).
Vamsacaritra
Life stories (caritra) of kings and heros of the dynasties.