A coil is a shape that is normally round and can be created with a circular pattern of lines and shapes. It is used to create the outline of an object that will be covered with another material.
A coil can also be created in order to produce a certain surface effect such as grooves, waves, or ribbing. It can also create items such as wire mesh or netting.
Coils can also be used to create shapes for cutting metal, plastics, and wood - they create an edge around an object's shape that will be cut out.
Coils are mainly used in construction