Do you have Photoshop Elements 7??
Elements is basically a stripped down version of CS.
I use Elements 9 which is still way too advanced for me. I'll probably never use all of the features. Its an amazing bit of software and I'm enjoying learning, albeit slowly.
Here is a comparison between elements and CS. Hope it explains the difference. The other difference is the price, which is a
massive difference.
http://graphicdesign.about.com/od/ho..._stamp_all.htm