Software Quality Assurance (SQA) and Software Quality Control (SQC) are the two important and vital areas of Software Engineering. It is not only necessary for delivering a bug free product but (in my opinion) it also helps developer to work without worry about (indirect) clients' reaction or (direct) reaction from boss, as it was QA department who passed the product :)
But, it also found that people around us don't have much awareness about it. Even there are number of software houses in Karachi developing applications without QA department... amazing!!! amazing not for software houses but for their clients :)
Here, I am giving few links about SQA & SQC that may help some one...
http://www.softwareqatest.com/
http://en.wikipedia.org/wiki/Software_testing
I like two quotes related to SQA, one topic of this post, and second is "We trust on Allah and else we test"