Given an 8x8 chessboard, your goal is to "cover" each space on the board with the fewest possible number of pieces. A space is "covered" if there is a piece on it, or if a piece on the board can be moved to that space in one move.
A trivially easy solution would be that a board could be covered with 64 pieces. If you place a piece on every square, every square is obviously covered.
A less trivial solution is 8 - fill an entire row or column with rooks. Obviously, each rook can cover all spaces in its row or column, so the board is covered.
Can this be done with less than 8 pieces? If so, what is the minimum number of pieces required?