How explain the draw ?

Hi everybody, i'm sorry if my question is not relevant, but i don't understand in this game why the computer decide to draw the game... Can someone explain me ?

Thanks

Threefold repetition. The same position 3 times in the game, after moves 40.Kf1, 42.Kf1 and 44.Kf1

I always think that the threefold repetition was with the same repetition of move by the two player. Ok thank you for your reponse.