Often incorrectly designated as 'move repetition', while 'repetition of position' would be a better term. If the same position with the same player to move has occurred three times, a draw can be claimed. Repetition of position most often occurs in endgames when neither player can make any progress.
It is not necessary that the positions follow each other the next moves or that the same moves precede the identical positions. A rather simplistic example to show how it might work is:
1.Nf3 Nf6 2.Ng1 Ng8 (the same position for the 2nd time) 3.Nc3 Na6 4.Nh3 Nh6 5.Ne4 Nf5 6.Nf4 Nd6 7.Nd5 Nc4 8.Nc3 Nb4 9.Nb1 Na5 10.Ng5 Nc6 11.Nf3 Nb8 12.Ng1 Nd5 13.Nc3 Nf6 14.Nb1 Ng8 (the same position for the 3rd time).
Although the King's Knights and Queen's Knights have exchanged their position, the final position on the chessboard is still identical.