Light emitting device, light emitting device package, and lighting device system

A light emitting device includes a substrate, a light emitting structure including a first conductive semiconductor layer having an exposed region, an active layer, and a second conductive semiconductor layer on the substrate, a first electrode on the exposed region of the first conductive semiconductor layer, and a second electrode on the second conductive semiconductor layer, wherein a side of the light emitting structure includes a first sloped side sloped from a reference plane, the first sloped side includes a concave-convex pattern having a concave-convex structure in which a first direction length is greater than a second direction length, the reference plane is a plane perpendicular to a direction in which the substrate faces the light emitting structure, and the first direction is a sloped direction of the first sloped side and the second direction is a lateral direction of the first sloped side.