Is a campsite lean to to set your tent up under?

A lean-to is a building with three sides and a sloping roof. Its use is not primarily to house a tent, but I suppose if it was big enough, then you could set one up under it. Lean-to's are generally small and use for storage or shelter. A tent is shelter, itself; there's no need to build a lean-to around it unless you want to keep the dew/rain off the tent.