Firstly, crystal and caramel are different.
Carapils is considered a dextrine type of malt that is proprietary to briess (and weyermann...)
all crystal malts are caramel malts, however all caramel malts may not be crystal malts. the process by which they are dried/roasted is different. Crystal malts generally have a light glazed appearance to them.
If you search this forum, or any other search (google, etc) you'll find a wealth of information describing the differences in malts. here's a quick, short article by breiss about crystal/caramel malts
http://blog.brewingwithbriess.com/is-it-crystal-or-caramel-malt/