The rook 飛車 moves any number of squares in a straight line — up, down, left or right — until it reaches the edge, one of your own pieces, or an enemy piece it can capture. It cannot jump.
Blocked and capturing
Your own pieces stop the rook before their square. An enemy piece stops it too — but the rook may capture it by moving onto its square.
The rook is the strongest unpromoted piece. When it promotes it becomes the dragon, which you'll meet in the promotion unit.
Try it
Try it: Capture the enemy piece with your rook.