How to test product quality in software?

Hi,
I am fresher and want to start a career in software testing company. An interviewer asked me how can Product Quality Assurance Testing be done? I dont know its answer.Can anybody hlep me?

‘Fresher’ in what kind of course, where?

I’d assume that step one would be to specify what the “software” in question was designed to do. And perhaps list specific forms of failures or outcomes that must be avoided. You can then define “Quality” in relevant terms for that specific software. Is that not the approach your course takes?

Remember that the main-loop software in the guidance system of a missile may not need an exit. :-)