Does cloud computing and grid computing are same?
No. Cloud means there is a server or group of them that are simply collecting or serving up data. Grid means processing of data which is shared by client computers that voluntarily join the grid. You usually do not have an option as to whether or not you end up using the cloud. Cloud computing is commonly used as a load balancing method for high capacity websites like Yahoo, Google, etc. Grid computing is commonly used for purposes such as curing diseases, finding the largest prime number, finding the billionth digit of pi, etc. One is storage, the other is processing.
