Processes

When an application is launched, it becomes a process: a special instance provided by the operating system that includes all the resources that are used by the running application. This program must be in Executable and Linkable Format (ELF), in order to allow the operating system to interpret its instructions. 

Process properties

Each process is a five-digit identifier process ID (PID), and it represents the process for all its life cycle. This means that there cannot be two processes with the same PID at the same time. Their uniqueness makes it possible to access a specific process by knowing its PID. Once a process is terminated, its PID can be reused for another process, if necessary...