From Online Dictionary of Crystallography
Transformation Euclidienne (Fr). Euklidische Abbildung (Ge). Transformazione Euclidiana (It). ユークリッド写像 (Ja). Transformación Euclidiana (Sp).
The Euclidean mapping or isometry is a special case of affine mapping that, besides collinearity and ratios of distances, keeps also distances and angles. Because of this, a Euclidean mapping is also called a rigid motion.
Euclidean mappings are of three types:
A special case of Euclidean mapping is a symmetry operation.