What characteristic defines stratus clouds?

Stratus clouds are characterized by their flat and blanket-like appearance, which makes them distinct from other types of clouds. These clouds typically cover the sky in a uniform layer, resembling a thick blanket that can obscure sunlight and create overcast conditions. They are often associated with light precipitation and can bring mist or light rain, contributing to their role in the weather. The flat structure of stratus clouds occurs at relatively low altitudes compared to other cloud types such as cumulus or cirrus clouds, which have more vertical development and appear fluffy or wispy. This defining characteristic of flatness and the extensive horizontal layering of stratus clouds highlights their unique formation within the cloud classification system.