Sectioning
Dividing the hair into neat parts and clipping them out of the way before cutting, colouring or braiding.
Also: sections
Sectioning means splitting the hair into separate areas, often the top, the two sides and the back, and holding each with a clip. Smaller subsections are then taken one at a time. It lets a stylist cut evenly, apply colour without missing patches, or plan a grid for braids or twists. The size of sections matters: small sections give precise cutting and slim braids; large ones are faster. Partings between sections are often made with the tail of a comb.