The storys protagonist, Jake Sully (Sam Worthington), is a former Marine who was wounded and paralyzed from the waist down in combat on Earth. Jake is selected to participate in the Avatar program, which will enable him to walk. Jake travels to Pandora, a lush jungle-covered extraterrestrial moon filled with incredible life forms, some beautiful, many terrifying. Pandora is also home to the Navi, a sentient humanoid race that are more physically capable than humans, although considered primitive. Standing three meters tall, with tails and sparkling blue skin, the Navi live in harmony with their unspoiled world. As humans encroach deeper into Pandora's forests in search of valuable minerals, the Navi unleash their formidable warrior abilities to defend their threatened existence. Jake has unwittingly been recruited to become part of this encroachment. Since humans are unable to breathe the air on Pandora, they have created genetically-bred human-Navi hybrids known as Avatars. The Avatars are living, breathing bodies that are controlled by a human "driver" through a technology that links the driver's mind to their Avatar body. On Pandora, through his Avatar body, Jake can be whole once again. Sent deep into Pandora's jungles as a scout for the soldiers that will follow, Jake encounters many of Pandora's beauties and dangers. There he meets a young Navi female, Neytiri, whose beauty is only matched by her ferocity in battle. Over time, Jake integrates himself into Neytiri's clan, and begins to fall in love with her. As a result, Jake finds himself caught between the military-industrial forces of Earth, and the Navi, forcing him to choose sides in an epic battle that will decide the fate of an entire world. [D-Man2010]
Avatar is set during the 22nd century on a small moon called Pandora, which orbits a gas giant, and is inhabited by the tribal Na'vi, ten foot blue humanoids that are peaceful unless attacked. Humans cannot breathe Pandoran air, so they genetically engineer human/Na'vi hybrids known as Avatars that can be controlled via a mental link. A paralyzed Marine named Jake Sully (Sam Worthington) volunteers to exist as an Avatar on Pandora, falling in love with a Na'vi princess and becoming caught up in the conflict between her people and the human military that is consuming their world. - IMDB