Concurrency isn't pretending to do multiple things at the same time, it's the concept of multiple things happening at once. Concurrency doesn't necessarily inv

Concurrency isn't pretending to do multiple things at the same time, it's the concept of multiple things happening at once. Concurrency doesn't necessarily involve parallel computation. Concurrency is just when you think about something as multiple things happening at once. This includes parallel computation, as well as premptive multitasking on a single CPU, as well as cooperative multitasking (including in green threads). It also includes coroutines, and the notion of an "iterator". Arguably dealing with time is also concurrency because it weave your program's thread of execution with the thread of time.