A rucksack is a bag you carry on your back, held in place by two straps that go over your shoulders. The word comes from German, where Rücken means “back” and Sack means “bag.” You might know it better as a backpack, though rucksack often refers to larger, sturdier bags used for hiking, camping, or military use.

Rucksacks are designed to distribute weight evenly across your shoulders and back, making it easier to carry heavy loads for long distances. A hiker might pack a rucksack with a sleeping bag, food, water, and supplies for a weekend camping trip. Soldiers carry rucksacks filled with equipment they need in the field.

While you might use a regular backpack for school books, a proper rucksack is built tougher and roomier, with extra pockets, stronger straps, and features like a frame to support heavier loads. When someone says they're rucking, they mean they're going on a long walk or march while carrying a loaded rucksack, often for exercise or military training.