home plate
The flat base in baseball where batters stand and score.
Home plate is the five-sided rubber slab where a batter stands in baseball or softball. It's the final base a runner must touch to score a run, which is why it's called “home.” Unlike the other three bases, which are square bags, home plate is flat and shaped like a house with a pointed roof facing the pitcher.
The plate helps define the strike zone: if a pitched ball crosses any part of it between the batter's knees and about the middle of their torso, and the batter doesn't swing, the umpire may call a strike. The catcher crouches behind home plate to catch pitches, and the batter stands in one of the boxes on either side of it.
When a runner races around all three bases and slides into home plate just before the catcher can tag them, that exciting play is called scoring a run or coming home. The whole point of baseball is to make it back home safely, which is why touching home plate feels like such an accomplishment. Players sometimes call it simply the plate or home, as in “He's heading home!” when a runner sprints toward it.