Pietra Grey in Chevron format is composed of pieces of tiles arranged in the classic zig-zag pattern. Whilst the herringbone pattern is made up using perfect rectangles, the chevron pattern uses parallelograms to give the iconic V shape. A picture's worth a thousand words, so these images should clear up any confusion.
Chevron tiles especially Pietra Grey is mostly used in bathrooms , kitcghens and splashbacks.