If a player moves a piece into a position that will allow it to remove the piece from a particular square in its next move, then that square is under attack.
Yes. A king can move to any square that is not attacked by the opponent. It can attack and take the opponent's pieces.
Because it just have 64 square'
The goal in chess, or the object of the game, is to checkmate your opponent's king. A king is in checkmate when he is attacked and no matter what move he attempts to make he is still being attacked (or in check). There are three ways to get out of check: move the king to a safe square, capture the checking piece, or block with another piece. If a player is in check and cannot get out of check, he is in checkmate and has lost the game.
The white square!! :)
Because chess is played on a 64 board square.
If by moving up to a square, you mean an adjacent square, yes, as long as the square is not threatened by any opposing piece. This is the only way a King can attack another piece. A King cannot enter any square that is attacked by an opposing piece, i.e. place himself in check. He also cannot castle across an attacked square (king's bishop 1-f1, or queen 1-d1), but it does not matter if the rook or queen's knight squares are attacked, because he does not cross or land on those squares. He cannot castle out of check.