Yes - the Scene saves everything, the various presets save some kind of settings so that you can reapply them later. Say you have that corridor in your screenshot set up with textures and other surfaces settings just the way you want it. You can save it as a Scene file, and load it in future by double-clicking the saved file in the Content palette (that will add it to whatever you have loaded already, it's the same as File>Merge) or you can go to File>Open and load just the corridor as a new scene. However, if you make several different versions of the corridor that have their own surface settings that can get tiresome; if instead you select the corridor and save a Material preset you can then apply it to the corridor to set the surfaces the way you had them. Presets let you try different combinations without having to delete the object and load a fresh version in its place.