Basics of Operating Systems Operating system can be defined as a software that acts as an interface between the User and hardware. It is a software that provides a working environment for the users application.
What is Operating System? A resource manager that manages the resource needed for all the applications in the background is an OS. OS is a software in which all common functions required to work on a Computer System have been put together.
Functions of Operating Systems
Types of Operating Systems
1)Batch Processing OS It takes a sequence of jobs in a batch and executes them one by one without any interrupt.
Example - IBM 7094
2)Multiprogrammed OS It means several programs in the Main Memory instead of a single program. CPU can switch to second process when the first process is waiting for any I/O Operation.
Example - Unix
3)Time Sharing OS In Batch and Multi-programmed OS, there is no provision of immediate response to the user. If one user submits, then it has to wait for the execution of all jobs in the queue and then it will get a chance. But in time sharing, the computer is shared among multiple users to execute all the jobs.
Example - Unix
4)Multitasking OS Multiple tasks of a single user can be opened on the System by Multiprogramming.
Example - Windows
5)Real-time OS In real time, response to user request goes within a fixed time frame, otherwise the application will fail. It is used to diffuse application.
Example - R T Linux
5) Distributed OS It is a multiprocessor OS. It works in WAN.
Example- Amoeba, Chorus
What is Process? When a program is in execution phase, then it's a process. When more than one program executes simultaneously, then it is a concurrent process. Concurrent process may be independent of each other. Then it is independent process. If one process is dependent on another ,that means a message will be sent to each other, then it is Interacting/Cooperating Process. When a process creates a sub-process, then a parent child relationship exist between them.
Difference between Program and Process A program is passive and static whereas a process is active and dynamic. A program cannot compete for resources but a process can do the same. A program has a code section only but there are code,data sections and stack program counter in process.
Implicit Process If the OS defines a process then it is called implicit process.
Example - To execute a C program, OS will create process for compiling Linking and loading.
Explicit Process If the process is defined by the user, then it is called Explicit Process.
Example - In real time system we can device the process in many segments.
Zombie Process When the process needs to be stopped or terminated but cannot be done as the parent process is not waiting for it.
Orphan Process It denotes the child process with no parent process associated with it.
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This article is good and explains the basic concepts about Operating Systems.It also gives details about Process and classification of a process.I would request the author to come up with articles pertaining to different pages of a process connected with the classification mentioned above.That would certainly explain the whole idea more beautifully.Overall a good article.Precise,crisp and clear.