Bhagavad Gita 10.23रुद्राणां शङ्करश्चास्मि वित्तेशो यक्षरक्षसाम्।वसूनां पावकश्चास्मि मेरुः शिखरिणामहम् ॥

Rudras are eleven in number. The ten vital airs (Pranas and the UpaPranas, which are five each) and the mind are the eleven Rudras. They are so called because they produce grief when they depart from the body. They have been symbolised in the Puranas as follows Virabhadra, Sankara, Girisa, Ajaikapati, Bhuvanadhisvara, Aherbhujya, Pinaki, Aparajita, Kapali, Sthanu and Bhaga. Among these Rudras, Sankara is regarded as the chief.Vasus are earth, water, fire, air, ether, sun, moon and stars. They are so called because they comprehend the whole universe within them. They have been symbolised in the Puranas as follows Apah, Dhruva, Soma, Dhara, Anila, Anala, Pratyusa and Prabhasa. Of these Anala or Pavaka (fire) is the chief.