Typically, wide receivers are often pegged to one specific position in the formation that best suits their strengths. Your X receiver is normally your #1 option in the passing game, but a guy that is a nuanced route runner that can work in all quadrants of the field and separate from coverage. Your Z receiver is normally your big play threat that is tasked with taking the top off the defense, traditionally challenging defenses vertically with impressive speed and/or body frame. Your Y receiver is normally your slot receiver that works the short and intermediate portions of the field, being asked to uncover quickly against slot defenders and linebackers to pick up first downs and be a reliable target on possession downs over the middle.