Traditional French knife technique sometimes referred to as "matchsticks." Typically done with raw vegetables, which are first cut on four sides into a rectangular shape of usually 2 inches long. The vegetable is then sliced into 1/8 inch slices. These slices are then stacked and sliced lengthwise again into 1/8 inch slices to create a square shape. The resulting julienne has a dimension of 2in x 1/8in x 1/8in.
These days the technique can also be achieved using other kitchen tools such as julienne peelers and mandolines with a julienne attachment.