We need to become very familiar with the Chess Board and all the squares.

Every square has its own name, using a letter from a to h and a number from 1 to 8.

Each horizontal line of squares is called a rank, so the seventh rank is the line of 8 squares from a7 to h7.

Each vertical line of squares is called a file, so the d file the line of squares from d1 to d8.

The diagonals are lines of squares which are all the same colour and touch only at the corner. The line of squares b1, c2, d3, e4, f5, g6, h7 make a diagonal.