In such a play, a defensive player catches a batted ball hit on the ground by the batter and throws the ball to a defensive player at first base before the batter can successfully reach the base, or records an out elsewhere via a fielder's choice.
[1] A batter is grounded out when a ball hits the ground immediately after being batted, commonly an infielder catches the ball and then throws it to a defensive player at first base to complete the out.
If the defensive players put out one baserunner during the same play in which a batter grounds out, the defensive team records a "double play".
There are other means of recording a double play that do not entail a ground out.
There are other means of recording a triple play that do not entail a ground out.