Definition:Chess/Chessboard/File

Definition
A column of a chessboard is known as a file.

It is identified by letter:
 * $\text a$ is the file on the edge of the board to the left of white (that is, to the right of black)
 * The files are lettered sequentially up to the file on the edge of the board to the left of black (that is, to the right of white).