Endgames
Passed pawn
A passed pawn has no enemy pawn ahead of it on its own file or either adjacent file. No opposing pawn can therefore block its path or capture it as it advances. Enemy pieces can still blockade or capture it.
A practical example
A white pawn on d5 is passed if there are no black pawns on c6–c8, d6–d8 or e6–e8. A black rook or king can still stop its advance.
A common mistake
Pushing every passed pawn immediately. An advance may lose protection or allow a blockade. A distant passer can already be valuable as a distraction without running straight away.
Try this in your next review
Count the moves to promotion and check blockading pieces, king support and enemy counterplay. Compare an immediate push with improving your pieces first.