Most Players - Especially the best - Can play multiple positions that are similar or the same, it really just depends on the formation used. If it was a 4-1-2-1-2 then the CM position would most likely be a CDM position with a CM in it. LM/LW are both technically the same based on the fact they both play all down the left side of the attack. CM's and CAM's switch positions regularly depending on how well they have played recently in that position and CF/ST depends on formation also. A CF and a ST are the same they both play as a main forward, CF is usually just a little bit further back on the formation sheet starting position than a striker.
Eden Hazard is a LW, not a LM
Steven Gerrard is a CAM, not a CM
Santi Cazorla is a CAM, not a CM
Wayne Rooney is a CF, not a ST