In popular and historical usage, "sharpshooter" and "marksman" are considered synonyms. Within the shooting sports and military usages today, however, sharpshooter and marksman refer to distinctly different levels of skill, which are never conflated. Specifically, in the US Army, "marksman" is a rating below "sharpshooter" and "expert". Four levels of skill are generally recognized today in both military and civilian shooting circles: unqualified, marksman, sharpshooter, and expert. Marksmanship badges for the three qualified levels are commonly awarded to both civilian and military shooters who attain proficiency in shooting higher than "unqualified".
The main difference between military marksmen and snipers is that marksmen are usually considered an organic part of a fireteam of soldiers and are never expected to operate independently, whereas snipers usually work alone or in very small teams with independent mission objectives. Snipers are also often tasked with responsibilities other than delivering long-range fire — specifically, conducting reconnaissance and directing coordinates for artillery fire or air strikes. Within the military, marksmen are sometimes attached to an infantryfireteam or squad (where they are known as designated marksmen) where they support the squad by providing accurate long-range shots at valuable targets as needed, thus extending the effective tactical reach of the fireteam or squad.
In the Middle Ages, in the first use of the term 'marksman' was given to the royal archers, or bowmen, of a palace guard, which was an elite group of troops chosen to guard a royal palace or the royalty. This was around the 10th century, although records of some 9th century English Kings show the listings of groups of marksmen specifically chosen for their militaries.