user9263: I know that there is 6 types of draws including mutual agreement, stalemate, insufficient material, 3 move repetition and the fifty move rule, but I do not know what is perpetual check. 

user11245: FIDE Laws of Chess do not recognize "perpetual check." They only recognize a case where the same position appears 3 times on the board. If it does, the player about to make the move that will cause it to appear for the 3rd time may claim a draw, but must do so before he makes his move. Once he makes his move, he no longer has any rights to claim a draw, because this can only be done while the player is still "on move".  Once he moves, his opponent is "on move".
The term "Threefold Repetition" is widely used, but misleading. Many players take it to mean what it seems to say, that a repetition has occurred 3 times, i.e. the position occurred once (no repetition), then again (1st repetition), then once again (2nd repetition; draw claim already available), and then one more time (3rd repetition, but 4th occurrence of the position; draw claim still available).  It's quite possible that 2 repetitions may occur, but the opponent may then vary to avoid a draw claim, in which case the 3rd repetition would not.  If this came about, the player who wanted to claim a draw missed his chance, and he won't get another.
It pays to understand the rules, not just know what people call them.

user2297: Perpetual check isn't a thing any more. But the idea is that one side demonstrates that they can keep putting the opponent's king in check, regardless of what the response is. Sooner or later it will turn into a threefold repetition or run afoul of the fifty move rule.

user9299: Well... Yes, it is still a thing, many top level games end in threefold repetition, but that is due to the perpetual check. So in a way, you can't draw a game by perpetual 'per se' but perpetual check can implicate threefold repetition occurring.

9263: <p>I know that there is 6 types of draws including mutual agreement, stalemate, insufficient material, 3 move repetition and the fifty move rule, but I do not know what is perpetual check. </p>
 11245: <p>FIDE Laws of Chess do not recognize "perpetual check." They only recognize a case where the same position appears 3 times on the board. If it does, the player about to make the move that will cause it to appear for the 3rd time may claim a draw, but must do so <em>before</em> he makes his move. Once he makes his move, he no longer has any rights to claim a draw, because this can only be done while the player is still "on move".  Once he moves, his opponent is "on move".</p>

<p>The term "Threefold Repetition" is widely used, but misleading. Many players take it to mean what it seems to say, that a <em>repetition</em> has occurred 3 times, i.e. the position occurred once (no repetition), then again (1st repetition), then once again (2nd repetition; draw claim already available), and then <em>one more time</em> (3rd <em>repetition</em>, but <em>4th occurrence of the position</em>; draw claim still available).  It's quite possible that 2 repetitions may occur, but the opponent may then vary <em>to avoid a draw claim</em>, in which case the 3rd repetition would <em>not</em>.  If this came about, the player who wanted to claim a draw <em>missed his chance</em>, and he won't get another.</p>

<p>It pays to understand the rules, not just know what people call them.</p>
 2297: <p>Perpetual check isn't a thing any more. But the idea is that one side demonstrates that they can keep putting the opponent's king in check, regardless of what the response is. Sooner or later it will turn into a threefold repetition or run afoul of the fifty move rule.</p>
 9299: <p>Well... Yes, it is still a thing, many top level games end in threefold repetition, but that is due to the perpetual check. So in a way, you can't draw a game by perpetual 'per se' but perpetual check can implicate threefold repetition occurring.</p>
