World-space modifiers act as object-specific space warps. They are carried with the object, but like space warps use world space rather than object space for their effects. World-space modifiers eliminate the need for binding to a separate space-warp gizmo, making them convenient for modifying a single object or selection set.
You apply world-space modifier like you apply standard object-space modifier. You can access world-space modifiers from the Modifiers menu, the Modifier List in the Modify panel, and applicable modifier sets. A world-space modifier is indicated by either an asterisk or the text “(WSM)” next to its name. (The asterisk or “(WSM)” distinguishes the world-space version from the object-space version of the same modifier, if one exists.)
When you assign a world-space modifier to an object, it appears at the top of the modifier stack, listed as a binding, in the same area as the space warp bindings.