Matters of Concurrency
If you try to multitask in the classic sense of doing two things at once, what you end up doing is quasi-tasking. It’s like being with children. You have to give it your full attention for however much time you have, and then you have to give something else your full attention.
—Joss Whedon, American screenwriter, film and television director, and comic book author
Concurrency is the ability to have multiple users (or processes/requests) access (change) shared data at the same time. The key is that when multiple processes or users are accessing the same resources, each user expects to see a consistent view of ...