All Classical dances developed out of folk dance. But classical dances began to be associated with spirituality whereas Folk dance continued to be celebrations of agricultural harvest or social gatherings like weddings, etc. – A celebration of Life.
Classical Dance evolved to become more demanding with technical aspects whereas Folk dance remained joyous and free.
Texts were written with clear principles of performance techniques and aesthetics which were laid down for a classical dance. They are stringent and demand rigorous training and practice to master.