Robustness testing is concerned with the correctness of the software when exceptional inputs are used. This differs from black box testing in that functional correctness in not concerned, just if abnormal terminations, machine crashes, or process hangs occur. Stress testing deals with amount of load a system can handle. This can be used to test the software on the platform in which it is running. This is not quite the same as a benchmark because it is trying to see if failures occur when the load is high or there is a burst of activities, not speed of execution.
Stress testing is very important on Internet websites.
There is the potential for millions of users, if your site or the server on which your site is hosted does not have the mechanism to deal with a heavy load, the reliability of you site may not be high. One simple and useful reliability check is to check browser compatibility. This is very important information to discover. Some browsers may not display images the correctly or at all. Another test that can be performed my not even be by you.