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UNIT-4, Linux Operating System, Process:- A process is the smallest executable unit in a computer. When user entered a, command at the shell prompt in Linux, it invokes a program. While this program is running,, it is called a process. That is, a process is an instance of a running program. In Unix, the, operating system schedules not the different programs to be executed but the different, processes to be executed., It is a program in execution which then forms the basis of all computation. The, process is not as same as program code but a lot more than it. A process is an 'active' entity as, opposed to the program which is considered to be a 'passive' entity. Attributes held by the, process include hardware state, memory, CPU, etc. For example, when you want to search, something on web then you start a browser. So, this can be process. Another example of, process can be starting your music player to listen to some cool music of your choice., Attributes of a Process:- A Process has various attributes associated with it. Some of the, attributes of a Process are:,  Process Id:- Every process will be given an id called Process Id to uniquely identify that, process from the other processes.,  Process state:- Each and every process has some states associated with it at a particular, instant of time. This is denoted by process state. It can be ready, waiting, running, etc.,  CPU scheduling information:- Each process is executed by using some process scheduling, algorithms like FCSF, Round-Robin, SJF, etc.,  I/O information:- Each process needs some I/O devices for their execution. So, the, information about device allocated and device need is crucial., States of a Process:- During the execution of a process, it undergoes a number of states. The, following states are:,  NEW- The process is being created.,  READY- The process is waiting to be assigned to a processor.,  RUNNING- Instructions are being executed.,  WAITING- The process is waiting for some event to occur (such as an I/O completion or, reception of a signal).,  TERMINATED- The process has finished execution., , Fig: States of a Process, XX##XX