From Academic Kids
A cumulus cloud is a cloud belonging to a class characterized by dense individual elements in the form of puffs, mounds or towers, with flat bases and tops that often resemble cauliflower. They are formed in the troposphere at a lower altitude than altocumulus, usually below 8000 feet (2400 metres). "Cumulus" is Latin for "heap", related to "accumulation".
They have often been described as cauliflower-like in structure. They occur at heights of 500-6000 meters in elevation from the earth and most often occur scattered or in dense heaped packs. They are formed due to buoyant upward convection during warm, anti-cyclonic summer weather.
- National Science Digital Library - Cumulus (http://www.nsdl.arm.gov/Library/glossary.shtml#Cumulus)