Ewoks are a race native to the Forest Moon of Endor. They resemble squat, bipedal bears and lead a tribal hunter-gatherer lifestyle. They fight and hunt with primitive but effective weapons and traps, and aided the Endor Strike Team of the Rebel Alliance in their attempts to destroy the shield generator protecting the Second Death Star at the Battle of Endor.
A faction inside the empire, Imperial Troopers were the soldier for the Galactic Empire and were used for a variety of situations. They came from civilian populations that lacked rebel sympathies, and were trained in academies across the galaxy.
Jedi are Force Sensitive beings that follow the light side of the force. They come from all over the galaxy and consist of multiple sentient species. They use a weapon called a lightsaber, and have played a major part in the Star Wars Galaxy for 20,000 years. They were mostly wiped out after Order 66, and the surviving Jedi went into hiding.
Rebels are terrorists/saviours of the Star Wars Galaxy. Following an extinct religion, the rebels undermined control and safety of the galaxy to stop the mistreatment of several minor species. After overthrowing the Empire, the rebels failed to set up a stable government, and started another war.