Ajiva (Sanskrit) is anything that has no soul or life, the polar opposite of "jīva" (soul). Because ajiva has no life, it does not accumulate karma and cannot die. Examples of ajiva include chairs, computers, paper, plastic, etc.
In Jainism, there are five categories which ajīva can be placed into. Out of these, four categories, Dharma (medium of motion), Adharma (medium of rest), Akasha (space) and Pudgala (matter) are described as the asti-kaya dravya's (substances which possess constituent parts extending in space) while the fifth category Kala is an anasti-kaya dravya (which has no extension in space).
Dharma (Jainism)
Dharmastikaya is formed from the two words: Dharma & Astikaya. Dharma here isn't referring to religion, but instead its referring to the medium of motion. Astikay itself is formed of two words: Asti & Kaya. Asti means space, body or mode and Kaya means collection. So Astikaya means a collection of spaces or regions. Dharmastikaya denotes the medium of motion for things in the universe. In the absence of this medium, living things (i.e. jiva) would not be able to move.
Adharmastikaya is also formed from two words: Adharma & Astikaya. Adharma in this case means the
medium of rest. In the absence of this medium, Living things or jiva would continuously move.
Ākāśa (Jainism)
The infinity of space, called ākāśa in Sanskrit, is divided by the Jain philosophy into two parts, namely, the lokākāśa (loka+ākāśa), that is the space occupied by the universe, and the alokākāśa (a not, and lokākāśa), the portion beyond the universe. The lokākāśa is the portion in which are to be found the remaining five substances, i.e., Jīvas, Matter, Time, Dharma and Adharma; but the alokākāśa is the region of pure space containing no other substance and lying stretched on all sides beyond bounds of the three worlds (the entire universe). At the summit of the lokākāśa is the Siddhashila (abode of the liberated souls).
Pudgala
The word Pudgala is made up of two terms: Pud means supplement (integration) and Gala means disintegration (division).