The Star Wars Jedi: Survivor essences are small blue beacons of light that offer you different rewards depending on which one you find. Stumbling across a health or force essence permanently increases your maximum capacity for that particular resource, so they're well worth looking out for while you're out and about exploring.
There are other types of essences, too. Another that's commonly found rewards you with XP and a Skill Point, while the rarest of the four types will give you a new or improved ability. Generally, there's no way of telling which one you'll get until you interact with it, so I've listed the locations of each one I've found below, broken down by region. Here are the Star Wars Jedi: Survivor essence locations.
