Kalialso known as Kalika , is the Hindu goddess associated with empowerment, shakti. The name Kali comes from kala, which means black, time, death, lord of death, Shiva. Since Shiva is called Kala—the eternal time—Kali, his consort, also means “Time” or “Death” (as in time has come). Hence, Kali is the Goddess of Time and Change. Although sometimes presented as dark and violent, her earliest incarnation as a figure of annihilator of evil forces still has some influence. Various Shakta Hindu cosmologies, as well as Shakta Tantric beliefs, worship her as the ultimate reality or Brahman. She is also revered as Bhavatarini (literally “redeemer of the universe”). Comparatively recent devotional movements largely conceive Kali as a benevolent mother goddess.
Kali is represented as the consort of Lord Shiva, on whose body she is often seen standing. Shiva laid in path of Kali, whose foot on Shiva subdues her anger. She is time manifestation of other Hindu goddesses like Durga, Bhadrakali, Sati, Rudrani, Parvati and Chamunda. She is the foremost among the Dasa Mahavidyas, ten fierce Tantric goddesses.
The Devi Mahatmyam describes:
Out of the surface of her (Durga’s) forehead, fierce with frown, issued suddenly Kali of terrible countenance, armed with a sword and noose. Bearing the strange khatvanga (skull-topped staff ), decorated with a garland of skulls, clad in a tiger’s skin, very appalling owing to her emaciated flesh, with gaping mouth, fearful with her tongue lolling out, having deep reddish eyes, filling the regions of the sky with her roars, falling upon impetuously and slaughtering the great asuras in that army, she devoured those hordes of the foes of the devas.
Kali destroys Raktabija by sucking the blood from his body and putting the many Raktabija duplicates in her gaping mouth. Pleased with her victory, Kali then dances on the field of battle, stepping on the corpses of the slain. Her consort Shiva lies among the dead beneath her feet, a representation of Kali commonly seen in her iconography as Daksinakali.
In the Devi Mahatmya version of this story, Kali is also described as a Matrika and as a Shakti or power of Devi. She is given the epithet Chamunda, i.e. the slayer of the demons Chanda and Munda. Chamunda is very often identified with Kali and is very much like her in appearance and habit.
Daksinakali
In her most famous pose as Daksinakali, it is said that Kali, becoming drunk on the blood of her victims on the battlefield, dances with destructive frenzy. In her fury she fails to see the body of her husband, Shiva, who lies among the corpses on the battlefield. Ultimately the cries of Shiva attract Kali’s attention, calming her fury. As a sign of her shame at having disrespected her husband in such a fashion, Kali sticks out her tongue. However, some sources state that this interpretation is a later version of the symbolism of the tongue: in tantric contexts, the tongue is seen to denote the element (guna) of rajas (energy and action) controlled by sattva, spiritual and godly creatures who served as assassins.
If Kali steps with right foot and holds sword in left hand she is considered to be Dakshina Kali. Dakshina Kali Temple has important religious associations with Jagannath Temple and it is believed that Daksinakali is the guardian of the kitchen of the Lord Jagannath Temple. Puranic tradition says that in Puri, Lord Jagannath is regarded as Daksinakalika. Goddess Dakshinakali plays an important role in the ‘Niti’ of Saptapuri Amavasya.
One South Indian tradition tells of a dance contest between Shiva and Kali. After defeating the two demons Sumbha and Nisumbha, Kali takes up residence in a forest. With fierce companions she terrorizes the surrounding area. One of Shiva’s devotees becomes distracted while performing austerities, and asks Shiva to rid the forest of the destructive goddess. When Shiva arrives, Kali threatens him, claiming the territory as her own. Shiva challenges Kali to a dance contest, and defeats her when she is unable to perform the energetic Tandava dance. Although in this case Kali is defeated, and is forced to control her disruptive habits, there are very few other images or other myths depicting her in such a manner.
Smashan Kali
If the Kali steps out with the left foot and holds sword in her right hand, she is terrible form of Mother, the Smashan Kali of cremation ground. She is worshiped by tantrics, the followers of Tantra. According to them one’s spiritual discipline practiced in smashan (cremation ground) brings success quickly. Sarda Devi, the consort of Ramakrishna Paramhansa worshiped Smashan Kali at Dakshineshwar.
Maternal Kali
Another myth depicts the infant Shiva calming Kali. In this similar story, Kali again defeated her enemies on the battlefield and began to dance out of control, drunk on the blood of the slain. To calm her down and to protect the stability of the world, Shiva is sent to the battlefield, as an infant, crying aloud. Seeing the child’s distress, Kali ceases dancing to take care of the helpless infant. She picks him up, kisses his head, and proceeds to breast feed the infant Shiva. This myth depicts Kali in her benevolent, maternal aspect; something that is revered in Hinduism, but not often recognized in the West.
Mahakali
Mahakali, literally translated as Great Kali, is sometimes considered as a greater form of Kali, identified with the Ultimate reality of Brahman. It can also simply be used as an honorific of the Goddess Kali, signifying her greatness by the prefix “Maha-“. Mahakali, in Sanskrit, is etymologically the feminized variant of Mahakala or Great Time (which is interpreted also as Death), an epithet of the God Shiva in Hinduism. Mahakali is the presiding Goddess of the first episode of the Devi Mahatmya. Here she is depicted as Devi in her universal form as Shakti. Here Devi serves as the agent who allows the cosmic order to be restored.
Sources : wikipedia & different online websites.