Depending on the system, linebackers can be designated by different names, broadly divided into "middle" or sometimes "inside" linebackers, who play behind the central part of the defensive line, and "outside" linebackers, who play further from the center. Some systems place linebackers on the same side of the field all the time, thus there can be a "left outside linebacker" and a "right outside linebacker". Other systems define a linebacker by the role he plays rather than the side of the field he plays on; a "strongside linebacker" plays on the same side of the field that the offense places their tight end (defined as the "strong" side of the field), while a "weakside linebacker" plays on the side away from the tight end (the "weak" side of the field, as it has fewer players).