Quality Assurance on the web, often referred to as QA, is a proof and review of a product or deliverable - in our case web applications and websites. QA is independent of the design and development processes in order to test a product’s many uses in the myriad of ways an enduser, especially those unfamiliar with the software, might. The QA process is expected to discover design issues and development errors while testing a product’s user interface (UI) and gauging the user experience (UX).
The QA process is important in any industry that creates products. However, when the products are web applications and websites, your deliverables are thrust into heavy use by numerous people very quickly. Having test data to review can assure everyone involved that your product is ready to hit the ground running for the 99%.