Elements is more like the 'Lite Version' of the software where as in actual Photoshop you are granted full access to tools, filters, ect.
Have you ever taken a drafting class, or any type of class that gives you "Student Edition" software to use in the classroom? It's a light version of the software, without all the special advanced functions. Photoshop Elements can be a useful tool for basic photo editing, providing simple fade effects, filters, etc; but you'll need the full fledged version to get most of your special effects (atleast get them the easy way)