Tetris: The tile-matching puzzle video game was released on June 6, 1984. Created by Russian video game designer Alexey Pajitnov in collaboration with Dmitry Pavlovsky and Vadim Gerasimov Tetris derived its name from the Greek numerical prefix tetra and tennis, Pajitnov's favourite sport. Alexey Pajitnov basedthe gameplay of Tetris around the concept of tetrominoes for the computer system Electronika 60.

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The game is played with 7 geometric shapes that will fall down on the playing field in random order, which the player has to position before they fall in place. The gameplay is mostly unending.

Tetris exploded into mainstream popularity over the years and is available for nearly every video game console and computer operating system, as well as on portable devices such as smartphone and handheld video game systems. It is also the first entertainment software to be exported from the USSR to the US and published by Spectrum HoloByte for Commodore 64 and IBM PC. Many scientific researchers say that playing Tetris for prolonged periods of time can also lead to more efficient brain activity during play. The game has gone on to spawn numerous sequels and variations over the years since it's release. Welltris, Hatris, Tetris & Dr. Mario are some notable examples.