Isometry group

An isometry group is a mathematical structure that consists of all isometries (distance-preserving transformations) of a metric space. In more formal terms, given a metric space \((X, d)\), the isometry group of that space is the group of all bijective mappings \(f: X \to X\) such that for any points \(x, y \in X\): \[ d(f(x), f(y)) = d(x, y).