Very simply, a cloud is "FOG" that is above the Earth's surface, rather than in contact with the ground. .
Clouds and fog are one and the same thing, very tiny droplets of c…ondensed water vapor, so small that they do not have enough weight to fall to the Earth, and consequently they just float around in the air..
IF and when enough of these droplets of condensed water vapor, collide and stick together, they become heavy enough for gravity to cause them to fall to Earth, and that is what we call rain. Other forms of precipitation occur when the vapor (or rain) is exposed to colder temperatures..
Clouds are formed when water vapour in the air is cooled and condenses as part of the water cycle . Clouds consist of billions of tiny water droplets (and even ice crystals) floating in the sky and appear in a variety of shapes and sizes depending on how and where they formed. I found this answer at http://www.rcn27.dial.pipex.com/cloudsrus/clouds.HTML Hope this helps. (MORE)