Backpacking combines hiking and camping in a single trip. A backpacker hikes into the backcountry to spend one or more nights there, and carries supplies and equipment to satisfy sleeping and eating needs.

A backpacker packs all of his or her gear into a backpack. This gear must include food, water, and shelter, or the means to obtain them, but very little else, and often in a more compact and simpler form than one would use for stationary camping. A backpacking trip must include at least one overnight stay in the wilderness (otherwise it is a day hike). Many backpacking trips last just a weekend (one or two nights), but long-distance expeditions may last weeks or months, sometimes aided by planned food and supply drops.

Backpacking camps are more spartan than ordinary camps. In areas that experience a regular traffic of backpackers, a hike-in camp might have a fire ring and a small wooden bulletin board with a map and some warning or information signs. Many hike-in camps are no more than level patches of ground without scrub or underbrush. In very remote areas, established camps do not exist at all, and travelers must choose appropriate camps themselves.

People are drawn to backpacking primarily for recreation, to explore places that they consider beautiful and fascinating, many of which cannot be accessed in any other way. A chance to be away from people. A backpacker can travel deeper into remote areas, away from people and their effects, than a day-hiker. However, backpacking presents more advantages besides distance of travel. Many weekend trips cover routes that could be hiked in a single day, but people choose to backpack them anyway, for the experience of staying overnight.

Almost all backpackers seek to minimize the weight and bulk of gear carried. A lighter pack causes less fatigue, injury and soreness, and allows the backpacker to travel longer distances. Every piece of equipment is evaluated for a balance of utility versus weight. Significant reductions in weight can usually be achieved with little sacrifice in equipment utility, though very lightweight equipment is often more costly.

A large industry has developed to provide lightweight gear and food for backpackers. The gear includes the backpacks themselves, as well as ordinary camping equipment modified to reduce the weight, by either reducing the size, reducing the durability, or using lighter materials such as special plastics, alloys of aluminium, and titanium, or making them consumable such as sleeping bags made of processed paper which can be burned. Designers of portable stoves and tents have been particularly ingenious. Homemade gear is common too, such as the beverage-can stove.

Some backpackers use lighter and more compact gear than do others. The most radical measures taken in this regard are sometimes called ultralight backpacking.

Due to the emphasis on weight reduction, a practical joke common in some circles is to secretly pack a small but relatively heavy luxury item, such as a soft drink, into another backpacker's pack. Then, once the group stops for a rest, the perpetrator retrieves the item, thanks the bearer for carrying it, and consumes it.