The extract operation is closely tied to part representations. Extract creates a single new part using only the geometry of the current representation of the selected part(s). For example, if the current representation of a part consisting of 3D elements is Border, the result of extraction will be a part consisting of all unshared 2D elements (the surface).

Extract is most often used to reduce the amount of information for a part (for example, for faster display or for geometry output) or to create a surface shell part - perhaps for subsequent cutting - of a 3D computational domain.