Question

what is cloud computing ?

Answer 1

Try this:
http://computer.howstuffworks.com/cloud-computing.htm

Answer 2

in basic a resilient system which is capable of serving applications over the browser.

Answer 3

Wikipedia says: Cloud computing means using multiple server computers via a digital network, as though they were one computer.
I say: The cloud is the name of that abstract collection of servers that process and store information through the web, that you can access through your computer. Is that helpful?