• A day pack is small and lightweight. It should be used for, as its name suggests, day hikes. It is not designed to carry a heavy burden.
• Use a soft pack/rucksack for one or two night trips when you do not have an enormous amount of weight on your back. It ranges in capacity from 2,500-3,500 cubic inches and in weight from 2-5 pounds.
• Internal frame backpacks are one of the two choices for multiple day trips with a heavy load. The "frame" - most often aluminum stays - is housed inside the pack.
• The external frame backpack is the second of two choices for long hikes with heavy loads. Compartments are attached to the rigid, aluminum tubing that makes up the frame.

The design features on an internal frame backpack and external frame backpack set them far apart from each other.

1. The external frame backpack consists of a rigid frame made of aluminum tubing with various compartments attached. External frame packs, with their multitude of pockets and compartment, keep the hiker organized.
2. The internal frame backpack is basically one large compartment into which you stuff all of your belongings. 2 aluminum stays are housed inside the pack, behind the shoulder harness. Many claim that internal frame backpacks are more comfortable because they "mold" to your back, unlike the more rigid external frame packs.