The End of the Game: Checkmate (Mate), Stalemate, Draw.
With a Checkmate the game is decided, but not every game ends with a Mate.
If he whose turn it is to move can make no legal move and yet his King is not Checked he is not Checkmated though the game necessarily is at an end. such a conclusion of the game is called a Stalemate, a useless, a false, an unproductive Mate, briefly "Stalemate." He who is Stalemated does not lose the game nor win it either, because loss of the game is suffered only by him who is "Checkmated," and an essential condition therefore is that the King should be in Check, whereas in a Stalemating position the King is not in Check.
Again when neither of the opponents believes he has the power to end the game by administering Checkmate, the game is undecided, "drawn," by mutual agreement. This agreement may be voluntary or compulsory. Compulsory when the two opponents repeat their moves, going backwards and forwards without changing their position, compulsory also when for fifty moves in succession no essential change, no advance towards the final goal can be demonstrated by either player. This demonstration, such is the accepted law, is achieved when during these fifty moves no capture nor the advance of a Pawn has been performed, for these are, by common consent, the outward, the visible signs of an essential change.
Here White is to move, Black menaces Checkmate in two ways, either by Qh3 captures h2 or plays to g2. White cannot defend the threat, he therefore tries to attack the opponent by giving Check with Qb6-a6. Black is forced to reply Ka8-b8. Now Qa6-b6 again checking. The pinned Pawn cannot capture, hence Kb8 -- c8 or -- a8. Again Qb6-a6, Ka8 (c8) -- b8. And the Checks have no end, the game is drawn by "Perpetual Check."