When a piece attacks the enemy king, it is called giving check. The player in check must remove the threat immediately.
There are three ways to get out of check: move the king to a safe square, put a piece in between, or capture the checking piece.
This time you are Black. Move your king off the e-file.
Now block: bring the bishop between the king and the rook.
This time capture the checking piece.
A king that is in check and cannot escape in any of these three ways is checkmated, and the game ends. In the next unit we'll learn checkmate and the other rules. Congratulations, you know the pieces!