Wrap is a deformer which allows you to deform geometries just like default wrap deformer comes with Autodesk Maya. Major different is that sWrap uses "point to point" based system and even the vertex orders are different in the geometries node calculates the deformation as expected in extremely fast manner thanks to its algorithm.
If the geometries are identical you can use "point to point" and if they are not you can use "ID does not matter" options. In both options sWrap works a lot faster than the wrap deformer which comes with Autodesk Maya.
This deformer is extremely useful when you need to separate geometries and drive them in order to export them into other packages like Side Effects Houdini. It allows you to export geometries without having slow scenes to deal with.