A quiz is compiled from several questions to be answered by individuals (or a team). A quiz is used in education to measure knowledge. It can be also used as a game. The quiz taker is required to answer the quiz questions correctly. Quizzes are usually scored in points.
A quiz writer needs to write and invent its own questions. This process is very awkward. A quiz in a WIKI way offers the quiz writer the possibility to use others (community) questions in its quiz and also write its own invented questions (which can be used by others).