Rules :: Learning how the Pawn moves
Here is a set of diagrams showing the different movements of the Pawn, every possible move is indicated with an arrow.
When the Pawn is on its initial square it can choose to move either one square or two squares. Once it moves from that initial square, it can only move one square at a time.
The pawn can capture an enemy piece by moving in diagonal (cannot capture by moving straight). The two pawns on the board have a choice of moving forward one square, or capturing a piece in diagonal.
These two pawns cannot move forward vertically, as they are blocked by an enemy piece. The pawn on the left cannot move at all, whereas the pawn on the right can capture the rook diagonally.
As we can see from these diagrams the Pawn can move initially move one or two squares, but then once it left it original position, can only move one square. A pawn can capture an enemy piece by moving diagonally.
Note, the pawn is the ONLY chess piece that cannot move backward.