On a public forum, the question was, "What are the most important aspects of software testing?"
A number of good answers were given, but all tended to emphasize finding errors. To me, that's a limited view of testing. I would say, instead, that the most important aspect of software testing is to provide information about the state of a software product. That is, not just errors, but what's good and bad about the product. And, by the way, what's just mediocre.
For instance, the speed of the product might not be in error, but could be good, bad, medicre, or perhaps acceptable to some or all possible users. It's the tester's job to document that.
Or, there may be a feature that works okay, but is not so easy to use. Is that an error? Who knows, but in any case, it's a fact that the sponsor of the project will usually want to know about, and providing that information is the tester's job.
One more example: if a tester merely finds and reports errors, small wonder that developers feel that testers are nattering nabobs of negativity. Test reports should describe what's good—what's wonderful—about a product, and testers must never forget that part of their job.
You can read more about important aspects of testing in my book, Perfect Software And Other Illusions About Testing.