The bishop 角行 moves any number of squares diagonally, until the edge, one of your pieces, or an enemy piece it captures.
The bishop on e5 covers both long diagonals through the centre.
At the start of the game both bishops are hemmed in by their own pawns. That is why so many games begin with g3g4: it opens the bishop's diagonal.
After g3g4, Sente's bishop on h2 looks all the way up to b8 — at Gote's bishop.
Try it
Try it: Move the bishop to every square it can reach. Your pawn on c3 blocks one diagonal; Gote's gold on g7 can be captured.