The ladder mate
The ladder mate is the first mate every beginner should learn: two rooks working together, driving the king backwards, rank by rank, like climbing a ladder, until it has no squares left.
Try to deliver the mate
Your turn: find the move that delivers checkmate. Drag the piece to the right square.
How to deliver it
One rook on a7 seals off the entire seventh rank, so the black king cannot come forward. The other rook swings to b8 and gives check on the back rank. The king is trapped between the two rooks with not a single free square. Checkmate.
How to defend
Against two rooks in the endgame your king is often alone and can do little, but you can make it hard: keep your king toward the centre as long as you can, and look for checks or attacks on one of the rooks that buy you time. Learn the pattern, and you will avoid walking straight into the ladder.