She is the daughter of Zeus and she is the Goddess of the Hunt, Moon, Forest, and the Protector of Children. She is the sister of Apollo and her Roman counterpart is Diana.
Artemis is one out of the five Goddesses and Hermes, to grant Wonder Woman her powers and abilities. Artemis granted Wonder Woman eyes of the hunter and unity with beasts.
In the new 52 Artemis helped Apollo bring Zola to Hera in exchange for Apollo gaining the empty throne of Zeus. She and Apollo battled Wonder Woman, Hermes and Lennox. In the fight she severely wounded Lennox and defeated Hermes. She later fights Wonder Woman and notes Diana doesn't have the dark edge to beat her before they are interrupted by Hera throwing Zola from Mount Olympus, before they go at each other again, Diana has removed her bracelets and effortlessly beats Artemis before bargaining her life for that of Zola and her child.
Like all of the Gods, this version of Artemis appears drastically different from the normal perception of the Greek Gods. In Artemis' case she has appeared as a nearly featureless humanoid with huge antlers growing from her forehead when she appeared before her fellow deity Demeter. But when she and her brother confronts Diana, Lennox and Hermes, she appears as an ablaster skinned woman (looking as if she was made of lunar rock) with no pupils or hair color, wearing a fur rimmed leather outfit and riding a large three-wheeled motorcycle that flies, her appearance may depend on the presence of the moon the same way it appears to dictate Apollo, the Sun God's, appearance.