What are the blocks in Tetris called?

The answer is: Tetraminos. You can say Tetris isn’t the best game of all time, but you’d be dead wrong. Unless you know someone living on a deserted island with nothing but pineapples to play with, everyone has played at least a few games of Tetris. Next time you play and the game won’t give you that damn line piece you need, now you can properly curse the Tetris gods for not giving you the right Tetramino.Source