The Rook is the strongest piece in Shogi. His large range makes it very useful for attack the enemy.
The Rook is called 飛車 (hisha) in japanese. It can moves any number of squares in orthogonal direction.
Promotion: the promotion of any piece except the King is possible in shogi when it arrives to the 7th, 8th or 9th row. In the most of cases you can choose to promote the piece or not (there a few exceptions for the knight, the lance and the pawn). A promoted Rook increase his movement capacity and is available to move diagonally one square. The promoted Rook is also called a Dragon that can be written 龍 or 竜 (Ryuu).
How to move the Rook – 飛車
How to move the Dragon – 龍