A backpack (also called rucksack, knapsack,
packsack, pack, or Bergen) is, in its simplest form, a
cloth sack carried on one's back and secured
with two straps that go over the shoulders, but there can be exceptions.
There are top-loading, panel-loading and hybrid styles of backpacks.
Panel-Loading Backpacks:
The main cargo compartments of a panel-loader open wide with curved access
zippers, this design makes this type easier to pack than a top-loader. Finding
a particular item may still require a little digging, but you
can usually locate it more quickly in a panel-loader.
A panel-loader has to be
angled or laid down to load, and for durability's sake, the zippers should be
heavy-gauge coils backed up with buckled compression straps. But for the most
part, a panel-loader is plenty durable, easier to load, and almost as
weather-proof as any top-loader, especially since you'd use a raincover with
each style.
There are also pack-makers have adopted high-volume hybrid
top-load/panel-load bag designs, so you can have your backpack either way.
