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1. Top results related to operating system definition computer science

   • Computer Architecture: How do applications communicate with an operating system?

     Top Answer

     Answered Oct 18, 2017 · 3 votes

     Too broad question, but some points (related to Linux; the principles should be the same for Windows, but you probably are forbidden to understand all of it) :

     The elementary system calls (those listed in syscalls(2)...) are invoked by an elementary machine instruction (e.g. SYSENTER or SYSCALL) which switches the processor into kernel mode (with the system call number and arguments passed through defined registers, following the ABI convention). Hence user-space code can be viewed as running in some virtual machine (defined by user-mode instructions + the system call primitives). BTW the Linux kernel can load kernel modules to e.g. add additional code (such as device drivers) in it, and that is done also thru system calls.

     The inter-process communication facilities are built above these system calls (perhaps used by the standard library in higher level functions, e.g. getaddrinfo(3) might interact indirectly with some DNS service, see nsswitch.conf(5)). Read Advanced Linux Programming for more details. In practice you'll need several server programs (and that idea is pushed to its extreme in microkernel approaches), notably (on recent Linux) systemd. Drivers and kernel modules are loaded by specific system calls and later are part of the kernel so are usable thru other system calls. Play with strace(1) to understand the actual system calls done by some Linux program. Some information is provided by the kernel thru pseudo file systems (see proc(5)...) accessible thru system calls.

     Every communication from user program to kernel is done by IPC (implemented by system calls). Sometimes, the kernel is doing an upcall to user code (on Linux, with signals).

     The Linux framebuffer (and the physical keyboard & mouse) is generally only accessed by a single server which other desktop applications communicate with using usual IPC facilities -sockets-, that server is the X11 or Wayland server.

     Read also some good book on Operating Systems, e.g. the freely downloadable Operating Systems: Three Easy Pieces

     For Windows, MacOSX, Android, it is very similar. However, since Windows (etc...) is a proprietary software, you might not be able to know all the details (and you might not be allowed to reverse-engineer them). In contrast, Linux is free software, so you can study its source code.

     My advice would be to understand in details how Linux work (this would take several years) and study some relevant source code (which is possible for free software). If you need an deep understanding of Windows, you might need to buy some source code license of it (probably millions of dollars) and sign an NDA. I don't know Windows at all, but AFAIK it is only defined by a huge API in C. Rumors tell that the Windows kernel is microkernel like, but Microsoft has economical interest to hide ugly implementation details.

     See also osdev.

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     1/5

   • Operating System - Difference Between Distributed System and Parallel System

     A distributed system is a model where distributed applications are running on multiple computers linked by a communications network. Sometimes it is also called loosely coupled systems because in which each processor has its own local memory and processing units. LOCUS and MICROS are some examples of distributed operating systems.

     Parallel Systems are designed to speed up the execution of programs by dividing the programs into multiple fragments and processing these fragments at the same time. Flynn has classified computer systems into four types based on parallelism in the instructions and in the data streams. 

     • Single Instruction stream, single data stream
     • Single Instruction stream, multiple data stream
     • Multiple Instruction stream, single data stream
     • Multiple Instruction stream, multiple data stream

     Advantages of Distributed Systems:

     • Scalability: Distributed systems can be easily scaled by adding more computers to the network.

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     2/5

   • Operating System - Difference Between Distributed System and Parallel System

     A distributed system is a model where distributed applications are running on multiple computers linked by a communications network. Sometimes it is also called loosely coupled systems because in which each processor has its own local memory and processing units. LOCUS and MICROS are some examples of distributed operating systems.

     Parallel Systems are designed to speed up the execution of programs by dividing the programs into multiple fragments and processing these fragments at the same time. Flynn has classified computer systems into four types based on parallelism in the instructions and in the data streams. 

     • Single Instruction stream, single data stream
     • Single Instruction stream, multiple data stream
     • Multiple Instruction stream, single data stream
     • Multiple Instruction stream, multiple data stream

     Advantages of Distributed Systems:

     • Scalability: Distributed systems can be easily scaled by adding more computers to the network.

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     3/5

   • Operating system file system block size?

     Top Answer

     Answered Nov 21, 2013 · 1 votes

     You can't have a big amount of different block sizes, that would be hell to implement and manage. I also think that some hardware limitations restrain what sizes you can use.

     Now the thing is, unless the amount of data you wish to store fits exactly in all the blocks you are using, then some space is going to be wasted in the last block.

     For example, if your block is one gygabyte long (hypothetically speaking), and you want to store a 1 or 2 bytes long file, you've just wasted nearly a gigabyte of disk space. All information is stored as blocks. You can't store half a block.

     Long blocks make for better performance, though, since the disk may spend more time fetching information from a block before proceeding to the next one. Also it's less blocks to track and manage.

     Linux is a fun operating system to play with because it can work with so many different file systems (as far as I remember you only get some variations of FAT and NTFS with Windows). You could read more about file system on this link:

     Linux System Administrators Guide: Chapter 5. Using Disks and Other Storage Media

     See section 5.10.5 for more info on advantages and disadvantages of small and big block sizes.

     So back to your question: having different block sizes like that allows you to optimize storage. You can minimize wasted space by switching to smaller blocks by the end of the file, while having as few blocks as possible to reduce I/O times.

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     4/5

   • System Programs in Operating System

     System Programming can be defined as the act of building Systems Software using System Programming Languages. According to Computer Hierarchy, Hardware comes first then is Operating System, System Programs, and finally Application Programs. Program Development and Execution can be done conveniently in System Programs. Some of the System Programs are simply user interfaces, others are complex. It traditionally sits between the user interface and system calls.  In the context of an operating system, system programs are nothing but a special software which give us facility to manage and control the computer’s hardware and resources. As we have mentioned earlier these programs are more closely with the operating system so it executes the operation fast and helpful in performing essential opeartion which can’t...

     • File Management &#x2013 A file is a collection of specific information stored in the memory of a computer system. File management is defined as the process of manipulating files in the computer system, its management includes the process of creating, modifying and deleting files.
     • Command Line Interface(CLI’s) : CLIs is the essential tool for user . It provide user facility to write commands directly to the system for performing any operation . It is a text-based way to interact with operating system. CLIs can perform many tasks like file manipulation,system configuration and etc.
     • Device drivers :Device drivers work as a simple translator for OS and devices . Basically it act as an intermediatry between the OS and devices and provide facility to both OS and devices to understand each other’s language so that they can work together efficiently without interrupt.
     • Status Information &#x2013 Information like date, time amount of available memory, or disk space is asked by some users. Others providing detailed performance, logging, and debugging information which is more complex. All this information is formatted and displayed on output devices or printed. Terminal or other output devices or files or a window of GUI is used for showing the output of programs.
     • File Modification &#x2013 This is used for modifying the content of files. Files stored on disks or other storage devices, we use different types of editors. For searching contents of files or perform transformations of files we use special commands.
     • Programming-Language support &#x2013 For common programming languages, we use Compilers, Assemblers, Debuggers, and interpreters which are already provided to users. It provides all support to users. We can run any programming language. All important languages are provided.
     • Program Loading and Execution &#x2013 When the program is ready after Assembling and compilation, it must be loaded into memory for execution. A loader is part of an operating system that is responsible for loading programs and libraries. It is one of the essential stages for starting a program. Loaders, relocatable loaders, linkage editors, and Overlay loaders are provided by the system.
     • Communications &#x2013al connections among processes, users, and computer systems are provided by programs. Users can send messages to another user on their screen, User can send e-mail, browsing on web pages, remote login, the transformation of files from one user to another.

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2. www.britannica.com › technology › operating-systemOperating system (OS) | Definition, Examples, & Concepts

   www.britannica.com › technology › operating-system

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   Jun 17, 2024 · operating system (OS), program that manages a computer’s resources, especially the allocation of those resources among other programs. Typical resources include the central processing unit (CPU), computer memory , file storage, input/output (I/O) devices , and network connections.

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     Answer: The first cell phone to feature the Android...

   • Multitasking

     Multitasking, the running of multiple programs (sets of...

   • Android

     Android, operating system for cellular telephones and tablet...

3. People also ask

   What is an operating system (OS)?

   • An operating system ( OS) is system software that manages computer hardware and software resources, and provides common services for computer programs .

   Operating system - Wikipedia

   en.wikipedia.org/wiki/Operating_system

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   Why do we need an operating system?

   • An operating system brings powerful benefits to computer software and software development. Without an operating system, every application would need to include its own UI, as well as the comprehensive code needed to handle all low-level functionality of the underlying computer, such as disk storage, network interfaces and so on.

   What is an Operating System (OS)? Definition, Types and Examples

   www.techtarget.com/whatis/definition/operating-system-OS

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   What is an example of operating system?

   • Examples of Operating Systems are Windows, Linux, Mac OS, etc. An Operating System (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is the most important type of system software in a computer system.

   What is an Operating System? - GeeksforGeeks

   www.geeksforgeeks.org/what-is-an-operating-system/

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   What is operating system & how does it work?

   • Operating System is a fully integrated set of specialized programs that handle all the operations of the computer. It controls and monitors the execution of all other programs that reside in the computer, which also includes application programs and other system software of the computer.

   What is an Operating System? - GeeksforGeeks

   www.geeksforgeeks.org/what-is-an-operating-system/

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4. www.geeksforgeeks.org › what-is-an-operating-systemWhat is an Operating System? - GeeksforGeeks

   www.geeksforgeeks.org › what-is-an-operating-system

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   • What Is An Operating System Used for?
   • Functions of The Operating System
   • Objectives of Operating Systems
   • Types of Operating Systems
   • How to Check The Operating System?
   • Examples of Operating Systems
   • FAQs on Operating System
   • GeneratedCaptionsTabForHeroSec

   The operating system helps in improving the computer software as well as hardware. Without OS, it became very difficult for any application to be user-friendly. The Operating System provides a user with an interface that makes any application attractive and user-friendly. The operating System comes with a large number of device drivers that make OS...

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   Resource Management: The operating system manages and allocates memory, CPU time, and other hardware resources among the various programs and processes running on the computer.

   Process Management: The operating system is responsible for starting, stopping, and managing processes and programs. It also controls the scheduling of processes and allocates resources to them.

   Memory Management:The operating system manages the computer’s primary memory and provides mechanisms for optimizing memory usage.

   Security: The operating system provides a secure environment for the user, applications, and data by implementing security policies and mechanisms such as access controls and encryption.

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   Let us now see some of the objectives of the operating system, which are mentioned below. 1. Convenient to use:One of the objectives is to make the computer system more convenient to use in an efficient manner. 2. User Friendly:To make the computer system more interactive with a more convenient interface for the users. 3. Easy Access:To provide eas...

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   Batch Operating System: A Batch Operating Systemis a type of operating system that does not interact with the computer directly. There is an operator who takes similar jobs having the same requirem...

   Time-sharing Operating System: Time-sharing Operating Systemis a type of operating system that allows many users to share computer resources (maximum utilization of the resources).

   Distributed Operating System: Distributed Operating Systemis a type of operating system that manages a group of different computers and makes appear to be a single computer. These operating systems...

   Network Operating System: Network Operating Systemis a type of operating system that runs on a server and provides the capability to manage data, users, groups, security, applications, and other ne...

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   There are so many factors to be considered while choosing the best Operating System for our use. These factors are mentioned below. 1. Price Factor: Price is one of the factors to choose the correct Operating System as there are some OS that is free, like Linux, but there is some more OS that is paid like Windows and macOS. 2. Accessibility Factor:...

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   Windows (GUI-based, PC)

   GNU/Linux(Personal, Workstations, ISP, File, and print server, Three-tier client/Server)

   macOS(Macintosh), used for Apple’s personal computers and workstations (MacBook, iMac).

   Android(Google’s Operating System for smartphones/tablets/smartwatches)

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   1. The Operating System is which type of software?

   (A) System software (B) Application software (C) Both a and b (D) None of the above Solution:

   2. Which of the following is not an example of an Operating System?

   (A) Windows (B) Linux (C) Mac OS (D) MS-Word Solution:

   3. Which characteristic property prevents unauthorized access to programs and data?

   (A) Security (B) Data Management (C) Device management (D) Control of system performance Solution:

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   An operating system is a system software that manages computer hardware and software resources and provides common services for programs. Learn about the functions, objectives, types, and examples of operating systems in computer science.

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5. Videos

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     introduction to operating system and its Functions | Operating System

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     Introduction to Operating Systems

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     1:38

     techtarget.com

     What is an Operating System (OS)? Definition, Types and Examples

     Mar 9, 2020

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6. www.techtarget.com › whatis › definitionWhat is an Operating System (OS)? Definition, Types and Examples

   www.techtarget.com › whatis › definition

   In this definition, learn what an operating systems is, how it works and manages all application programs in a computer, and about the types and functions of OSes.

   • Author: Stephen J. Bigelow

   • Video Duration: 2 min

7. en.wikipedia.org › wiki › Operating_systemOperating system - Wikipedia

   en.wikipedia.org › wiki › Operating_system

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   An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time , mass storage , peripherals, and ...

8. www.freecodecamp.org › news › what-is-an-osWhat is an OS? Operating System Definition for Beginners

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   Aug 31, 2021 · With this understanding we can describe an Operating System ( OS) as a software that manages computer hardware and software resources and provides common services for computer programs. In simple English we can say an OS is an interface between the user and the machine that makes it easy for the user to achieve different tasks with ease.

9. edu.gcfglobal.org › en › computerbasicsComputer Basics: Understanding Operating Systems - GCFGlobal.org

   edu.gcfglobal.org › en › computerbasics

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   What is an operating system? An operating system is the most important software that runs on a computer. It manages the computer's memory and processes, as well as all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's language.

10. techterms.com › definition › operating_systemOperating System Definition - What is an operating system?

    techterms.com › definition › operating_system

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    May 4, 2023 · An operating system (OS) is software that controls a computer's core functions and communicates with the hardware and allows programs to run. Learn about the different types of OS, their features, and how to choose one for your needs.