1.Ra2
Okay, lets look at rooks, now. Unlike bishops, which move diagonally, rooks move straight up and down the rows and columns of squares...
1...Ra8
...and they can either move one square or more than one square, as far as they can go.
2.Re2
They can move sideways...
2...Ra4
They can move forward...
3.Re1
And they can moves backwards...
3...Rxa3
And they can either capture an opponent's piece that's right next to it...
4.Rh1
Ra6
5.Rxh6
Or they can pick one off from the other side of the board, again just like queens and bishops.
5...Ra8
But remember, they only move vertically...
6.Rh1
Rg8
...and sideways.
7.Rd1
Now, remember when we looked at how the bishops move, I said that a bishop will stay on the same color square for the entire duration of the game..
7...Rb8
8.Rd2
Rooks don't have that problem...
8...Rb5
Rooks can land on any color square that's in their path.
9.Ra2
Therefore, that ability by itself makes a rook more valuable than a bishop..
9...Re5
10.Ra6
Re4
11.Rxg6
because a bishop can only visit half the squares on the board.....
11...Rxb4
...but a rook can visit all 64 squares...
12.cxb4
...uh, oops, that is, if we don't drop our rook to a lowly pawn like I just did here. (Do as I say, not as I do....)
12...Kd7
Now rooks are also particularly useful for keeping an eye on the opponent's king.
13.Kf3
Ke7
Notice how black's king here is limited to moving back and forth on his back two rows (ranks) on his end of the board.
14.Kf4
Kf7
He can't cross the third row of squares because the rook is firmly in control of that rank, and the black king would be moving into check if he tried to cross.
15.Ra6
No, sorry, you can't have my rook.
15...Ke7
Black would dearly love to move his king forward to guard his last pawn, but he can't because of the white rook.
16.Kxf5
...So the pawn falls to one of white's other
pieces, in this case; the king.
16...Kf7
....sigh, back and forth, back and forth.....
17.Ra7+
Check! Oh, what's this?! Something new! Can black's king finally get out of the dungeon? No, he can't. Because white has wisely positioned HIS king directly OPPOSITE the back king (separated by the blockaded row). Black cannot move forward. (That's called "opposition".)
17...Kf8
...and he can't move to the side anymore,
either, because the rook controlled the row, so he was reluctantly forced to move into an even smaller area on the board.
18.Ke6
Kg8
...any idea what's coming up, yet?
19.Kf6
Black's running out of room....
19...Kh8
20.Kg6
Black has just one move left.....
20...Kg8
....do you see it? What can white do to end this game in one move?
21.Ra8#
Exactly. White used a combination of his king and rook to force black's king to the back row and then, after forcing black to move his king directly OPPOSITE white's king, checkmated him with the rook. Black can't move the king forward because of the white king, and can't move side to side because the rook covers all the squares on the row. Black is checkmated. White wins. Cool! 1-0