The gymnasium inAncient Greece as a training facility for competitors in public games. It was also a place for socializing and engaging in intellectual pursuits. A game is structuredplaying, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out forremuneration, and from art, which is more often an expression of aesthetic or ideological elements. However, the distinction is not clear-cut, and many games are also considered to be work (such as professional players of spectator sports/games) or art. Key components of games are goals, rules, challenge, and interaction. Games generally involve mental or physical stimulation, and often both. Many games help develop practical skills, serve as a form of exercise, or otherwise perform an educational, simulational, or psychological role.