Playing field of 2048 represents a square 4×4, on which two tiles are already opened in the starting position.
They can be arranged as desired, the initial arrangement options are "2" and "2", "2" and "4", "4" and "4" (most rarely). The tiles can be moved to one of the four sides (if this is not prevented by the location), and when two tiles of the same face value collide with each other, they become one tile, the value of which is doubled. During one turn a tile can be stacked in different places of the playing field, but only once to increase its value. In other words, if in a row are "2", "2" and "4", then per move you can combine only "2" and "2" into "4", and the resulting "4" with a block of the same value - only during the next move.
The peculiarity of 2048 is that the whole playing field moves to the border, not individual columns or rows. After each such move a new tile of value "2" (with 90% probability) or "4" (with 10% probability) appears on a random empty cell. The game is considered lost if you have no moves left (all squares are filled with tiles that are not possible to combine with each other). To win in the original version of the game you had to collect a tile face value of "2048" (hence the name). Later, the algorithm was slightly modified, which allowed to continue the game after getting 2048.
The game also includes a point calculation - the sum of all tiles connected during the game. The current points for the game and the best personal score are displayed in the upper right corner.
All of the above may seem quite complicated in words, but in fact it takes a couple of minutes to understand the rules and the principle of the game in detail.