Before we are going to learn the algebraic chess notation we have to identify each square of the chessboard with a unique coordinate. The files are labelled with the lower-case letters a through h, from the left of the player with the white pieces. In addition the ranks are numbered from 1 to 8. The result is that each square of the board is uniquely identified by its file letter and rank number, as shown for some example squares in the diagram below.