Usability testing is a technique used to evaluate a product by testing it on users. Usability testing is a black-box testing technique. The aim is to observe people using the product to discover errors and areas of improvement.
Security Testing means how well our system protects against unauthorized internal or external access. The process to determine that an information system protects data and maintains functionality as intended.
Quality is not a new concept. It is in effect sincecenturies.In olden days if someone pinpointed the e defect in craftsman's work, he/she was feeling humiliated.I mean to say the perception of quality goes on changingwith time.See More