Turnaround time - Time required for a particular process to complete, 
                from submission time to completion. It is equal to the sum 
                total of Waiting time and Execution time.

Response time - The time taken in a program from the issuance of a command 
                to the commence of a response to that command.
                (i.e., the time-interval between submission of a request, 
                and the first response to that request, not the output .)