Pawn chain

Pawns of the same color standing on a diagonal and defending one another. The simplest example of a pawn chain:

A pawn chain can be mobile, that is, one of its links can be pushed forward when the chance arises, or blocked, when it runs straight up against a similar pawn chain of the opponent. A pawn chain is most often attacked at its base, since the bottom pawn, unlike the links above it, is not defended by a pawn.