Akasha (or Akash, Ākāśa IPA: [aːkaːʃə]) is the Sanskrit word meaning "æther" in both its elemental and metaphysical senses.
Hinduism: In Hinduism, Akasha means the basis and essence of all things in the material world; the first material element created from the astral world, (Akasha (Ether), Earth,Water,Fire,Air,) in sequence). It is one of the Panchamahabhuta, or "five elements"; its main characteristic is Shabda (sound). In Sanskrit the word means "space", the first element in creation. In Hindi, Marathi and Gujarati, and many other Indian languages, the meaning of Akasha has been accepted as sky.
The Nyaya and Vaisheshika schools of Hindu philosophy state that Akasha or aether is the fifth physical substance, which is the substratum of the quality of sound. It is the One, Eternal, and All Pervading physical substance, which is imperceptible.
According to the Samkhya school of Hindu philosophy, Akasha is one of the five Mahābhūtas (grand physical elements) having the specific property of sound.
Buddhism: In Buddhist phenomenology Akasha is divided into limited space (ākāsa-dhātu) and endless space (ajatākasā).
The Vaibhashika, an early school of Buddhist philosophy, hold Akasha's existence to be real.
Ākāsa is identified as the first arūpa jhāna (arūpajhāna), but usually translates as "infinite space.