What is an operating system?
An operating system (OS) is the software that controls all other application programs in a computer after being installed into the system first by a boot program. Through a specified application program interface(API), the application programs seek services from the operating system. Additionally, users can communicate directly with the operating system by using a user interface, such as a graphical user interface (GUI) or a command-line interface (CLI).
Why to use an operating system?
The creation of software for computers benefits greatly from an operating system. Without an operating system, each program would have to have both its own user interface (UI) and the complete code required to manage all low-level computer operations, such as disc storage, network connections, and other things. This would greatly increase the size of any program and render software development difficult given the wide variety of underlying technology available.
Instead, a lot of routine operations, such as transmitting a network packet or showing text on a display or other conventional output device, can be delegated to system software, which acts as a bridge between applications and hardware. Applications may interface with the hardware in a consistent and repeatable manner without having to be aware of any specifics about the hardware thanks to the system software.
That system software—the operating system—can support nearly unlimited number of applications as long as they all access the same resources and services in the same way. By using a standard and understandable interface, users may control, configure, and manage the system hardware, greatly reducing the time and coding needed to design and debug an application.
The operating system depends on a sizable library of device drivers after installation to customize OS services to the unique hardware environment. As a result, even though every application may make the same request to a storage device, the operating system (OS) receives that call and utilizes the relevant driver to transform it into the actions (commands) required for the underlying hardware on that particular computer. Today's operating systems offer a complete platform for identifying, configuring, and managing a variety of hardware, including processors, memory devices and memory management, chipsets, storage, networking, port communication, like VGA, HDMI, and USB, and subsystem interfaces, like PCI Express (PCIe).
Operating System Functions
An operating system delivers three key functions: a UI via a CLI or GUI; application activation and management; and identification and exposure of system hardware resources to those programs — often via a defined API.
User Interface(UI):
Every operating system needs a user interface (UI), which enables users and administrators to communicate with the OS to install, configure, and even diagnose the OS and its supporting hardware. CLI and GUI are the two main categories of UI that are offered.
The CLI, or terminal mode window, offers a text-based user interface where users enter certain commands, parameters, and arguments relating to particular operations using the conventional keyboard. Users interact with the GUI, or desktop, using movements given by human interface devices such touchpads, touchscreens, and mouse devices. An icons and symbol-based visual interface is offered by the GUI, sometimes known as the desktop.
The GUI is largely utilized by end users who are interested in manipulating files and programs, such as double-clicking a file icon to open the file in the program that is associated with it. Advanced users and system administrators who frequently need to handle a variety of highly specific and repetitive commands, such as writing and executing scripts to install new personal computers (PCs) for staff members, continue to choose the CLI.
Application Management and Control
Every application is launched and managed by an operating system. This typically supports a variety of behaviors, such as timesharing between multiple processes, or threads, so that different tasks can share the time of the available processors; handling interruptions that applications produce to get a processor's immediate attention; ensuring there is enough memory to execute the application and its associated data without interfering with other processes; carrying out error handling that can gracefully remove an application's processes and performing error handling that can remove an application's processes.
Additionally, an operating system may include APIs that let applications use hardware and OS features without having to be aware of low-level OS or device information. A Panels API, for instance, can make it possible for a program to read and write files to a storage device, generate GUI components like dialogue windows and buttons, and more. Applications are nearly usually designed to operate on the operating system that they are intended to run on.
An operating system can also provide apps the following services:
- The operating system chooses which apps should run in what sequence and how much time should be given to each application before giving another application a turn under a multitasking operating system, where numerous programs can run concurrently.
- It manages input/output (I/O) to and from connected hardware devices, including dial-up ports, printers, and hard drives.
- It communicates the operation status and any potential faults to each application or interactive user, as well as to the system operator.
- It can relieve the starting application of this effort by offloading the management of batch jobs, such as printing.
- An operating system can control how to split the application so that it executes on more than one processor at a time on systems that support parallel processing.
An operating system is necessary for all major computer platforms (hardware and software) and is occasionally included in them. Operating systems must be built with a variety of capabilities to accommodate diverse form factors.
Hardware management
The identification, configuration, and provision of programs with open access to underlying computer hardware components is the responsibility of an operating system. The OS will install relevant device drivers when it recognizes and identifies hardware, allowing the OS and programs running on the OS to use the devices without having to be specifically aware of the hardware or devices.
The operating system is in charge of locating the appropriate printer and installing the required printer drivers so that a program just has to call and not utilize any codes or instructions that are exclusive to that printer. Similar issues arise with additional hardware, including USB ports, networking ports, graphics hardware, motherboard chipsets, graphics processing units (GPUs), and storage hardware, including Serial-Attached SCSI (SAS) disc adapters and discs that have the appropriate file system formatted.
The OS locates and sets up logical and physical devices for use, and it often stores this information in a standardized format, like Windows Registry. To maintain the greatest device performance and security, drivers should be updated by device makers on a regular basis, and the OS should do the same. The OS also installs and configures new drivers when devices are changed.
Types and Examples of Operating System
There are innumerable operating systems that cater to a broad range of hardware and user demands, despite the fact that the essential functions of an operating system are universal.
General-Purpose OS
A general-purpose OS is any of a number of operating systems designed to run a variety of programs on a variety of hardware, allowing a user to execute one or more tasks or apps at once. A general-purpose operating system (OS) may be installed on a wide range of desktop and laptop models and can run a variety of programs, including accounting software, databases, web browsers, and games. To guarantee that programs can successfully share the large variety of computer hardware present, general-purpose operating systems often concentrate on process (thread) and hardware management.
The following are common desktop operating systems:
Windows
Microsoft's main operating system, Windows, is the industry norm for personal and commercial computers. The GUI-based OS was first introduced in 1985 and has subsequently been published in several iterations. The fast growth of personal computing was primarily attributed to the approachable Windows 95.
Mac OS
The operating system for Apple's Macintosh family of desktops and workstations is called Mac OS.
Unix
An operating system with many users called Unix was created to be flexible and adaptable. One of the earliest operating systems built in the C language was Unix, which was created in the 1970s.
Linux
A Unix-like operating system called Linux was created to provide PC users a free or inexpensive alternative. Linux is known for being an effective and quick system.
Mobile Operating system
Mobile operating systems are created to meet the particular requirements of computing and communication-focused mobile devices like smartphones and tablets. In contrast to traditional PCs, mobile devices frequently have less constrained computational power, therefore the OS must be simplified to save resource consumption while yet providing enough power for one or more operating programs. Mobile operating systems frequently place a strong emphasis on responsiveness to users, efficient performance, and careful attention to data processing activities like media streaming. Mobile operating systems include Apple iOS and Google Android, for instance.
Embedded Operation System
Not every computing gadget is multipurpose. Computers that need an operating system are found in a wide range of dedicated devices, such as home digital assistants, automated teller machines (ATMs), aviation systems, retail point of sale (POS) terminals, and internet of things (IoT) devices. The main distinction is that because the linked computer hardware only performs one key function, the OS is much simplified and focused on both performance and robustness. The OS must function swiftly, without crashing, and gracefully manage all problems in order to function continuously under all conditions. The OS is typically offered on a chip that is built into the physical device. For instance, a medical device utilized as a part of a patient's life support system will require an embedded OS that must function properly in order to keep the patient alive. One example of an embedded OS is embedded Linux.
Network Operating System
Another customized OS designed to allow communication between devices connected to a local area network is the network operating system (NOS) (LAN). In order to construct, exchange, and dissect network packets, a NOS offers the communication stack required to comprehend network protocols. The idea of a dedicated NOS is now essentially out of date because network communication is handled primarily by other OS types. For instance, Windows 10 and Windows Server 2019 both provide with complete networking features. For some networking devices, such as routers, switches, and firewalls, the idea of a NOS is still in use. Manufacturers may utilize exclusive NOSes, such as the Cisco Internetwork Operating System (IOS), RouterOS, and ZyNOS.
Real-time Operating System
The maker of the computer equipment may decide to utilize a real-time operating system when it needs to interface with the outside world within continuous and recurrent time limits (RTOS). An expansive factory or power plant, for instance, may have its activities managed by an industrial control system. In addition to sending signals to operate valves, actuators, motors, and numerous other devices, such a facility would also create signals from a wide variety of sensors. In these circumstances, the industrial control system must react to altering real-world conditions swiftly and reliably; otherwise, tragedy may occur. Buffering, processing latencies, and other delays that are entirely acceptable in other kinds of operating systems must not exist in an RTOS. FreeRTOS and VxWorks are two RTOSs as examples.
There are certain operating system types that resemble others, therefore the differences between them are not always clear. For instance, networking features present in a conventional NOS are frequently included in general-purpose operating systems. Similar to how a mobile operating system can often run many apps at once like other general-purpose operating systems, an embedded operating system sometimes contains elements of an RTOS.
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