In baseball, a double play occurs when the defending team gets two outs before the pitcher resets. A majority of double plays have two force outs; when a runner is on first base, the defending team gets a force out at second base followed by one at first base.
A less common double play, the "strike 'em out, thrown 'em out" double play, happens when the pitcher strikes the batter out and throws a baserunner out. This most often occurs when the baserunner attempts to steal second base, but the catcher can also throw to any base and get an out if the baserunner doesn't return in time. Teams can only get three outs per inning, so it's impossible to get a double play with two outs in one inning.