Jakku is a desert planet similar in type to Tatooine that has appeared in the past movies. It is home for Rey, a young female scavenger who comes into possession of BB8, the new star Wars droid. Both the Rebel Alliance now known as the Resistance and the First Order come to the planet as they both believe information that could lead them to the location of Luke Skywalker lies on the planet.
The planet lies in the Unknown Regions which when you look at a star map, the area is on the left side of the map. It is the perfect location if you want something hidden and not found. Rey was left there as a young child by her parents whose identities have not yet been revealed in the films.
The planet was the location for a secret Imperial base that was used as a stepping stone for the Unknown Regions of the galaxy. Now all that's left of the planet is a lawless place for thieves, outlaws and refugees.
There are two villages shown in the film, the first is Tuanul Village where Poe Dameron is to meet his contact and get information about Luke Skywalkers location. It is here that Kylo Ren attacks and Finn decides to desert the First Order.
The second location is Niima Outpost which is where Rey sells her scavenged goods to make a living. It is the place that Finn meets Reys. Also in the town is the Millennium Falcon which Han Solo had lost but gets back in the film.
Unlike Tatooine which was filmed in Tunisia, Jakku was filmed in Rub' al Khali in Abu Dhabi. One of the reasons because it was unsafe to film in Tunisia at the time because of the Arab Spring uprising that was going on at the time.
During the war between the Rebel Alliance and the Galactic Empire, there was a battle in space and on the ground. There were a lot of wreckage spewed all over the planet. Rey scavenges parts from the vehicles such as the fallen Star Destroyer and exchanges them for food rations with Unkar Plutt. Rey has taken up home in the wreckage of a fallen AT-AT transport ship.
The fight never appeared in any of the main Star Wars films but is playable in the updated Star Wars Battlefront game. The Battle of Jakku is featured in the Star Wars : Aftermath books. It tells of a final battle between the Galactic Empire and New Republic. The Battle of the Moon of Endor saw the death of Emperor Palpatine, it didn't signal the end of the war. Although Palpatine was dead, it did not result in the large scale surrender of the the Galactic Empire forces.