Starfighters of the Resistance are helpless without the fuel that helps them zig and zag around combat elements of the First Order. Someone has to keep the crews ready to fight and each and every moment. That job falls largely to refueling droids like B-U4D, nicknamed Buford.
As part of ground crew operations at the Resistance base on D'Qar, Buford works tirelessly (like most droids) and manages fuel supplies without complaint. In "The Force Awakens," Buford roams the background of a few scenes, doing his part to keep the army working against the evil Empire.
Droids like Buford are a perfect example of the depth and dimension of the "Star Wars" universe. Even droids that find only a few frames of movie time — often far in the background — have backstory and personality that drives them onward. Whether they use their potential for good or for evil, the Force is a part of them all ... even the most unappreciated droids in the galaxy.