What is an Operating System?
An operating system is a program designed to run other programs on a computer. A computer’s operating system is its most important program. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.
The operating system of a large computer system has even more work to do. Such operating systems monitor different programs and users, making sure everything runs smoothly, without interference, despite the fact that numerous devices and programs are used simultaneously. An operating system also has a vital role to play in security. Its job includes preventing unauthorized users from accessing the computer system.
There are multiuser, multiprocessing, multitasking, multithreading, and real-time operating systems. A multiuser operating system enables multiple users to run programs simultaneously. This type of operating system may be used for just a few people or hundreds of them. In fact, there are some operating systems that are used to allow thousands of people to run programs at the same time.
A multiprocessing operating system allows a program to run on more than one central processing unit (CPU) at a time. This can come in very handy in some work environments, at schools, and even for some home-computing situations. Multitasking operating systems work a little differently; they make it possible to run more than one program at a time. Multithreading operating systems are even more different, allowing varied parts of one program to be used simultaneously.
Real-time operating systems are designed to allow computers to process and respond to input instantly. Usually, general-purpose operating systems, such as disk operating system (DOS), are not considered real time, as they may require seconds or minutes to respond to input. Real-time operating systems are typically used when computers must react to the consistent input of information without delay. For example, real-time operating systems may be used in navigation.
Today’s operating systems tend to have graphical user interfaces (GUIs) that employ pointing devices for input. A mouse is an example of such a pointing device, as is a stylus. Commonly used operating systems for IBM-compatible personal computers include Microsoft Windows, Linux, and Unix variations. For Macintosh computers, Mac OS X, Linux, BSD, and some Windows variants are commonly used.
What Is a Multitasking Operating System?
multitasking operating system is any type of system that is capable of running more than one program at a time. Most modern operating systems are configured to handle multiple programs simultaneously, with the exception of some privately developed systems that are designed for use in specific business settings. As with most types of communications technology, the multitasking operating system has evolved over time, and is likely to continue evolving as communication demands keep growing in many cultures.
With older examples of the multitasking operating system, managing two or more tasks normally involved switching system resources back and forth between the two running processes. The system would execute tasks for one, freeze that program for a few seconds, and then execute tasks for the other program. While this approach did create a short time lag for the operator, this lag was usually no more than a few seconds, and still offered considerable more efficiency than the older single-task operating system.
Over time, popular incarnations of the multitasking operating system were developed that used a different approach to allocating resources for each active program. This created a situation where virtually no time lag occurred at all, assuming that the equipment driving the system had adequate resources. For the end user, this meant the ability to perform several tasks simultaneously without any waiting for the system to release or redirect resources as each task completed in turn.
The typical multiple operating system requires more resources than the simple operating systems that were common for desktop computers in the late 1970s and early 1980s. Newer systems require platforms with a considerable amount of random access memory (RAM) as well as other type of virtual memory. If the resources are not available to drive the various applications that are open and being executed, the system may slow to a crawl, or possibly even shut down an application or two if that is the way the system is configured to prevent overload.
Today, most desktop, laptop, and netbook operating systems function with some type of multitasking operating system. Even equipment such as automatic teller machines or ATMs still make use of some type of multitasking system, using a series of programs to check balances and execute the requests made by users. There are also examples of movie ticket stub systems that are able to perform several tasks at once, including posting receipts for tickets purchased, even as the system generates and dispenses the purchased tickets.
How Do I Choose the Best Computer Operating System?
To choose the best computer operating system (OS) you should consider your needs from your computer, as well as the types of programs you would like to run. Some operating systems can be quite user friendly and provide you with a fairly high number of tools and customization options, even if you are not the most experienced computer user. Other systems may provide you with far greater tools, but can be fairly daunting if you do not have a good amount of experience in using computers. You should also consider what types of programs or software you wish to run on your computer, as some types of computer operating systems tend to have better support from different applications.
A computer operating system is the program that is initialized during the start-up process of the computer, and then takes over the general functioning of the computer. It allows a computer user to organize, navigate, and utilize the various files and programs installed on the computer. In general, the computer operating system can be one of the most important pieces of software chosen by a computer user. As such, there are numerous options out there and the best OS for a user will typically depend on individual preferences and needs.
Linux Computer Operating System
Free Computer Operating System
Android Computer Operating System
Computer Operating System Software
Computer Operating System Originally
Typically, there is no single right answer as to what computer operating system is best. There are preferences and one OS may be better for one user, while another OS will better suit the needs of another user. If you have a decent understanding of computers and can navigate a graphical interface fairly well, then most mainstream operating systems will likely work well for you. Most personal computer (PC) users tend to use a version of Microsoft® Windows®, and computers bought pre-manufactured will typically come with Windows® installed on the computer.
Similarly, most users of Apple® computers use the Mac OS X® that usually comes installed on those computers. If you are using a computer operating system already installed on your computer and have had no problems with it, then you have probably found the best OS for you. There are also more advanced operating systems that allow far greater customization, such as open source systems like Linux® and other UNIX systems.
These can be quite user friendly, and the unparalleled customization of these systems have made them favorites among programmers and computer enthusiasts. The number of applications and programs that support these systems, however, is typically far fewer than those that support Windows® and even the Mac OS X®. You should be sure that whatever programs you like to run — graphics or video editors, games, and even web browsers — are properly supported by any computer operating system you may be considering using.
Description of the operating system
For a computer to be able to operate a computer programme (sometimes known as application or software), the machine must be able to perform a certain number of preparatory operations to ensure exchange between the processor, the memory and the physical resources (peripherals).
The operating system (sometimes referred to by its abbreviation OS), is responsible for creating the link between the material resources, the user and the applications (word processor, video game, etc.). When a programme wants to access a material resource, it does not need to send specific information to the peripheral device but it simply sends the information to the operating system, which conveys it to the relevant peripheral via its driver. If there are no drivers, each programme has to recognise and take into account the communication with each type of peripheral!
The operating system thus allows the "dissociation" of programmes and hardware, mainly to simplify resource management and offer the user a simplified Man-machine interface (MMI) to overcome the complexity of the actual machine.
Roles of the operating system
The operating system has various roles:
- Management of the processor: the operating system is responsible for managing allocation of the processor between the different programmes using a scheduling algorithm. The type of scheduler is totally dependent on the operating system, according to the desired objective.
- Management of the random access memory: the operating system is responsible for managing the memory space allocated to each application and, where relevant, to each user. If there is insufficient physical memory, the operating system can create a memory zone on the hard drive, known as "virtual memory". The virtual memory lets you run applications requiring more memory than there is available RAM on the system. However, this memory is a great deal slower.
- Management of input/output: the operating system allows unification and control of access of programmes to material resources via drivers (also known as peripheral administrators or input/output administrators).
- Management of execution of applications: the operating system is responsible for smooth execution of applications by allocating the resources required for them to operate. This means an application that is not responding correctly can be "killed".
- Management of authorisations: the operating system is responsible for security relating to execution of programmes by guaranteeing that the resources are used only by programmes and users with the relevent authorisations.
- File management: the operating system manages reading and writing in the file system and the user and application file access authorisations.
- Information management: the operating system provides a certain number of indicators that can be used to diagnose the correct operation of the machine.
Components of the operating system
The operating system comprises a set of software packages that can be used to manage interactions with the hardware. The following elements are generally included in this set of software:
- The kernel, which represents the operating system's basic functions such as management of memory, processes, files, main inputs/outputs and communication functionalities.
- The shell, allowing communication with the operating system via a control language, letting the user control the peripherals without knowing the characteristics of the hardware used, management of physical addresses, etc.
- The file system, allowing files to be recorded in a tree structure.
Multi-threaded systems
An operating system is known as multi-threaded when several "tasks" (also known as processes) may be run at the same time.
The applications consist of a sequence of instructions known as "threads". These threads will be alternately active, on standby, suspended or destroyed, according to the priority accorded to them or may be run simultaneously.
A system is known as pre-emptive when it has a scheduler (also called planner), which, according to priority criteria, allocates the machine time between the various processes requesting it.
The system is called a shared time system when a time quota is allocated to each process by the scheduler. This is the case of multi-user systems which allow several users to use different or similar applications on the same machine at the same time. the system is then referred to as a "transactional system". To do this, the system allocates a period of time to each user.
Multi-processor systems
Multi-processing is a technique that involves operating several processors in parallel to obtain a higher calculation power than that obtained using a high-end processor or to increase the availability of the system (in the event of processor breakdown).
The term SMP (Symmetric Multiprocessing or Symmetric Multiprocessor) refers to an architecture in which all processors access the same shared memory.
A multiprocessor system must be able to manage memory sharing between several processors but also to distribute the work load.
Real time systems
Real time systems, used mainly in industry, are systems designed to operate in a time-constrained environment. A real time system must also operate reliably according to specific time constraints; in other words, it must be able to properly process information received at clearly-defined intervals (regular or otherwise).
Here are some examples of real time operating systems:
