A pawn island is a group of connected pawns. For example, in the following position:
White has two pawn islands:
Black has three:
Even though the pawn on
h7 is more commonly known as “isolated pawn”, it’s
still considered it a pawn island, after all it presents the same challenges as
any other pawn island.
A group of connected pawns, often referred as pawns chain, is best attacked at its base. As the base of the pawns chain represents a weakness, each pawn island in your position gives targets to your opponent.