What on earth are you talking about? I assume these are models of a certain brand of backpacks, but unless you provide further descriptions or photos, I don’t suppose anyone’s gonna help you.

Some clarification would be nice. My guess is that he is talking about a travel pack [url=‘http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=2785080’]example[/url]) vs. an internal frame backpack ([url=‘http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=32396235’]example[/url]).

I suppose it’s a matter of preference and how long you expect to be wearing it.. Travel packs tend to be designed to try to fit within carry-on requirements. A number also come with a day pack you can detatch. I went with an internal backpack mostly because I do a lot of backpacking/camping besides the trip(s) to Europe, so I get a lot of use that way. True, I have to check the bag and my bag is a little bigger than what most people use, but I haven’t had a problem… yet.

The most important thing is to find something you are comfortable wearing. Even if you order something online (http://www.campmor.com/ has pretty good deals), I recommend going to an outdoor story to try on some of the designs so you can feel what it is like. The store should show you how to adjust the packs as well.

A travel pack is a pack designed specifically for backpacking travel, Eagle Creek being the most well-known maker of such packs. A "camping pack" would be something like an Arc Teryx pack designed for outdoor use. Both can have internal frames. They aren’t hugely different, and you won’t have a bad trip because you didn’t buy a pack designed primarily for travel. The major differences are in details. Advantages that SOME travel packs have are the aforementioned detachable daypack, straps that don’t hang off as much, and the fact that they are front loading instead of top-loading. These features can be nice, but are not necessary. Your biggest priorities should be fit and quality, and I know budget also comes into the picture. If you can find a good quality, well-fitting travel pack in your price range go for it, but if not don’t hesitate to buy an outdoor pack that fits well and meets your budget requirements.

Travel Packs:
-Cheaper (except Eagle Creek and some premium brands)
-Often have detachable daypacks
-Usually panel-loading for easy access to stuff
-Easier to pack and organize; more suitcase-y
-Usually designed for travelling in cities and small towns, loading off and on trains, short walks around cities from train stations to hostels, etc.

Camping Packs (or Internal Frame packs):
-Usually more expensive, for the quality ones anyway, but some of the lower-range ones can be quite affordable
-Generally have a better suspension system for carrying loads comfortably for longer periods of time
-Often top-loading or small side zip loading, so can be harder to pack and accesss
-Generally don’t have detachable daypacks, though some are compatible for hydration or "camel" packs
-Designed more for the outdoors but common among travellers as well
-More styles and selection available, so can usually accommodate a wider range of shapes and sizes and fit more people properly

If you’re planning on taking a messenger bag or another kind of bag instead of a daypack, the lack of a detachable daypack may not be a big deal to you. Even if you do take a daypack, you can just buy it separately and carry it in front.

The best thing to do is probably to go to a store like REI or MEC or whatever you have locally, and try on a bunch of packs to see what fits comfortably and what you prefer.