A shack is a small, crudely built shelter or dwelling, usually made from cheap or salvaged materials like scrap wood, metal sheets, or whatever else the builder could find. Picture a tiny house thrown together with mismatched boards, maybe a rusty tin roof, gaps between the walls where wind whistles through. Shacks are rough and simple, often lacking electricity, running water, or proper insulation.

People build shacks when they have few resources but need shelter. In some poor areas around the world, entire neighborhoods consist of shacks. During America's Great Depression in the 1930s, homeless people built temporary shacks from cardboard, tin, and scrap lumber in camps nicknamed Hoovervilles.

But shack isn't always negative. Some people use the word affectionately for rustic cabins or simple beach houses. A family might have a fishing shack by the lake where they spend weekends, or an artist might work in a shack in the woods. In these cases, the word suggests something humble and unpretentious rather than desperate poverty.