Changes the current component selection by selecting the polygon edges associated with the original selection and then extends the selection of the edges as polygon faces in either direction along the polygon mesh.
For example, if you have a polygon mesh comprised of four-sided polygons (quads) with one interior vertex selected and then choose Select > Convert Selection > To Face Path, four edges are initially selected on the mesh (based on their association with the selected vertex) and then a path of faces are selected outward from the four edges.
Many of the convert selection features are available from the context sensitive polygon marking menu when you press 
+ 
whenever a polygon component is selected.