Euclidean lattice of traditional crystal

does the subject want to ask "what is the Euclidean lattice of traditional crystals"? The method of describing the structure. Traditional crystal Euclidean lattice is a basic way to describe crystal structure. In Euclidean geometry, distance and angle are common quantities to describe geometric structure, but in crystal structure, distance and angle are equally important. Euclidean lattice is a method to describe crystal structure by measuring the distance and angle between atoms in crystal structure.