In chess, the horizontal rows of squares on the board are called:

In chess, the horizontal rows of squares on the board are called ranks, and the vertical columns of squares are called files.

The chessboard:

• A chessboard has 64 squares arranged in an 8 x 8 grid, alternating between light and dark colours.
• The board is placed so that each player has a light square in the right-hand corner ("light on the right").

The ranks are numbered 1 to 8, starting from White's side. White's pieces start on ranks 1 and 2, and Black's on ranks 7 and 8.

The files are lettered a to h, from White's left to right.

Each square has a name made from its file and rank, such as e4 or d5. This is the basis of algebraic notation, the standard way of recording chess moves.

The diagonals are lines of squares of the same colour running at an angle; bishops move along them.

Pieces and moves:

• Each player starts with 16 pieces: one king, one queen, two rooks, two bishops, two knights and eight pawns.
• The queen starts on a square of her own colour (white queen on d1, black queen on d8).
• Special moves include castling (moving the king two squares towards a rook, with the rook jumping over), en passant (a special pawn capture) and pawn promotion (a pawn reaching the last rank becomes another piece).

History:

Chess developed from the ancient Indian game "Chaturanga" around the 6th century CE, which spread to Persia as "Shatranj". The world governing body, FIDE, was founded in 1924 in Paris.

Why not the other options?

• ✗Files are the vertical columns (a to h).
• ✗Diagonals are slanting lines of squares used by bishops.
• ✗"Columns" is not the official chess term; the correct term is files.