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

A light emitting device includes a substrate (100), a light emitting structure (105) including a first conductive semiconductor layer (120) having an exposed region, an active layer (130), and a second conductive semiconductor layer (140) on the substrate, a first electrode (170) on the exposed region of the first conductive semiconductor layer, and a second electrode (160) on the second conductive semiconductor layer, wherein a side of the light emitting structure includes a first sloped side (142) sloped from a reference plane, the first sloped side includes a concave-convex pattern (180) having a concave-convex structure in which a first direction length (111-1) is greater than a second direction length (111-2), 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.