In Jainism, Akashastikaya refers to space which is infinite, imperceptible and eternal. It is inferred as the condition of extension. All substances have extension which is afforded by space. Akashastikaya is arupin (formless) and is all pervasive. It is a single substance having infinite pradesha and hence classified under the astikaya group.
Two kinds of spaces are distinguished. Lokakasha refers to
filled space where motion is possible and alokakasha or empty space where
motion is not possible. While the former includes all the worlds where life and
movement is present, the latter is described as stretching infinitely beyond the
former.