Tetromino are geometric 2-dimensional shapes formed by combining 4 unit squares. It takes its name from the combination of the Latin word “tetra” meaning four and domino. They are also called "Tetrads", "Bloks" and "Tetrominoes". If we add depth to these shapes and increase them to 3 dimensions, they are called "Tetracube". For Tetris, this depth is again 1 unit. For Tetris Effect: Connected, we can examine these shapes in 2D as Tetromino.

Since tetrominoes are made up of unit squares, the length of each square is also 1 unit. They show orthogonal characteristics as the shape they form alone or when interlocking. For Tetris games and Tetris Effect: Connected is a kind of puzzle game played with Tetrominos. The tetrominos can thus be stacked inside the rectangular container without leaving any gaps when they come together. This is the main gameplay mechanic of the Tetris games and Tetris Effect: Connected.

• They consist of orthogonal polynomials.
  
  
• Tetrominoes consist of 7 shapes in Tetris, which they are named with the letters S, Z, J, L, O, T and I.
  
  
• S, Z, J and L Tetrominos have the property called "Chirality". Chirality specifies that in geometry, a shape cannot be mirrored by rotating it. Therefore, although the S and Z Tetrominos are mirror images of each other, they cannot be converted to each other by rotating them in the 2D Tetris plane. Likewise, this is also true for the J and L Tetrominos.
  
  
• Chirality is out of question for O, T, I Tetrominos.
  
  
• There are 12 free and 18 unilateral polynomials and 63 fixed polynomials in tetrominoes.
  
  
• Tetrominos, which are free polynomials, have the property of chirality.
  
  
• Tetrominos, which are one-sided polynomials, are shapes that do not change with any rotational or translational motion.
  
  
• Tetrominos, which are constant polynomials, are shapes that do not change with any rotation, translation, or reflection motion.