The box is marked with cones into four bands, measured along the pitch away from the batsman. The scorer taps whichever band the ball reached — the cones make the call, and only the first thing the ball touches counts.
Zone 0 is the band around the batsman. Zone 1 runs to the bowling crease. Zone 2 starts at the bowling crease, where the stumps stand, and runs to the front net. Zone 3 is the front net itself. The side netting is marked in the same colours, since that is where the cones stand.
The dashed line across the middle is the non-striker's crease: where he stands, and as far as a run ever goes.