Infielders are baseball players who occupy positions on the infield, which is the area of the field within the diamond formed by the bases. The main infield positions include first baseman, second baseman, shortstop, and third baseman. Their primary responsibilities involve fielding ground balls, catching line drives, and making quick throws to get runners out. Infielders play a crucial role in defense, as they are often involved in plays that require quick reactions and strong throwing skills. They work closely with each other and the pitcher to execute plays, such as double plays and cutoffs, to prevent the opposing team from advancing on the bases.