There are two types of backpacks. External Frames and Internal Frames. What's the difference you ask?

External-Frame Backpacks - The frame is on the outside. Duh, I hear you saying. These are the originals, I'm sure most of our first backpacks are one of these babies. As technology moves away from the external pack to the now more preferred (by most) Internal-Frame Backpacks, why would anyone want one of these dinosaurs? Here are some reasons some people prefer to always use External-Frame Packs. Price. External packs are generally cheaper. They can be cooler on the body as they hold the pack away the back, allowing air flow and they tend to be lighter.

Internal-Frame Backpacks - This highly engineered backpacks are designed for ease of travel and comfort. They conform tight to the body with the load riding low against the back which provides excellent balance and maneuverability which can be an incredible asset in rough or slippery terrain. They are more expensive than external frame packs and can be a nightmare when you need something at the bottom of the pack when you're mid hike. Some backpackers complain about sweating to death with these packs tight against their backs on a hot day.

What one needs to do is not judge to quickly on appearances or prices. Next to your footwear, your backpack is the next most important piece of equipment you'll take on a hike. So choose wisely and make sure it fits you and your needs properly.