High concurrency in Web
Have you ever wondered what kind of request volume or how many users a high-concurrency web application can support? An application that can only handle several hundred or several thousand PVs per day is not considered a high-concurrency system.
However, there is no clear definition online as to what constitutes high concurrency. Note that the term concurrency here does not refer to concurrency in programming. For information on concurrency and the difference between concurrency and parallelism in programming, please refer to this article.