What is a process and process table? What are different states of process?
A process is an instance of a computer program that is being executed; basically the functions of a computer program are broken down into process.
A process table is a table which lists the processes that are undergoing. This table must be saved when the CPU switches from running one process to another in a multitasking system. The benefit of a process table is that it allows a suspended process to be restarted at a later time as if it had never been stopped.
There are three different states of process: running, ready, or waiting. A running process is a process that is currently running. A ready process is one that is ready to be executed, whereas a waiting process is one that is waiting to be executed.
These categories primarily refer to resource allocation. The running state means that the process has all the resources it need for execution and it has been given permission by the operating system to use the processor. However, only one process can be in the running state at any given time. All other processes must be either ready, or waiting. In the waiting state, the process is waiting for some external event to occur such as user input or a disk access, while in the ready state, the process is waiting for permission to use the processor.