Processes

A process is an instance of an application that is being executed. Each time an application is started, a process is started for it. A process has a state; things such as handles to open resources, a process ID, data, network connections, and so on, are part of the state of a process and can be accessed by the threads inside that process.

An application can be composed of many processes, a common practice for example for internet browsers. But implementing a multi-process application brings challenges that are out of the scope of this book. For this book, we will cover the implementation of applications that run in more than one thread, but still in a single process.