A braid (sometimes called a plait) is a three-dimensional structure created by interlacing a minimum of three strands of flexible materials such as yarns, wire, straw, leather or hair. In some cultures — such as in Japan — braids are constructed by using multiples of 4 elements (e.g., 4, 8, 12, etc.).  In other cultures, even or odd numbers of elements can be used — for instance, 7 elements in straw plaiting, or 22 elements in Victorian hair braiding.

A braid is usually a long and narrow structure in which each component moves through and interlace with the other components. Unlike loom woven structures, most (but not all) braids do not have a fixed warp or weft. Rather, the elements alternate between acting as warp and weft.

Because a braid provides a stronger structure than a non-interlaced yarn by itself, braided structures are present in many cultures all over the world where they serve both utilitarian and decorative functions.

Sometimes braids are made by hand without the aid of equipment, sometimes stands are used to help with tension, speed and consistency. The most common stand is a type of round stand with a system of weights and counterweights. Japan is currently the only culture where multiple types of stands are used to facilitate the construction of a variety of braids.