Simplify the following text for a Grade 4 native English-speaking person.
Original: It is also common to refer to a rook pawn , meaning any pawn on the a-file or h-file , a knight pawn ( on the b - or g-file ) , a bishop pawn ( on the c - or f-file ) , a queen pawn ( on the d-file ) , a king pawn ( on the e-file ) , and a central pawn ( on either the d - or e-file ) .
Simplified: Any piece in front of a pawn , white or black , stops its moving . In the picture at right , the pawn on c4 may move to c5 , while the pawn on e2 may move to either e3 or e4 .