Nirjara is one of the seven fundamental principles, or Tattva in Jain philosophy, and refers to the shedding or removal of accumulated karmas from the atma (soul), essential for breaking free from samsara, the cycle of birth-death and rebirth, by achieving moksha, liberation.
Literally meaning "falling off", the concept is described first in chapter 9 of the classical Jain text, Tattvartha Sutra (True nature of Reality) written by Acharya Umasvati, in 2nd century CE, the only text authoritative in both Svetambara and Digambara sects of Jainism. Later it also finds mention in Dravyasamgraha (Compendium of substances), a 10th-century Jain text by Acharya Nemichandra.
Nirjara is preceded by stoppage of karma accumulation, or samvara, thereby ending asrava or influx of karma which leads to bandha or bondage due kasaya or passions of the soul, namely, krodha (anger), lobha (greed), mana (ego) and maya (deceit), besides raaga (attachment) and dvesa (hatred). Dravyasamgraha explains that the soul becomes dim due to the dust of karmic matter, thus nirjara itself offers a way to clear the soul, and ultimately leading to moksha, liberation.
Nirjara is of two types, Bhava Nirjara, modification of soul which leads to separation of karmic matter from the soul, and Dravya Nirjara, actual separation of karmic matter from the soul. In turn, bhava nirjara is of two types, Savipaka and Avipaka.