Do you know, that… ?
Depending on the situation, SolidWorks some operations may be used interchangeably. For example, surgery planar surface it is similar (it relates to a flat loop) do Fill surface. However, the latter can immediately connect to the surface and form a further body.
Just look also Surface pulled the profiles and Area Boundary.
border area, if the geometric conditions are satisfied, It allows you to instantly create a solid body. In older versions it was necessary to use a separate operation Knit surface.