An operating system is the basic software that allows the efficient administration of a computer, since it handles the hardware and the rest of the programs and applications. Therefore, this operating system acts as an intermediary between the user and the computer. It is also necessary for the operation of the device, because it provides commands to the device and enables interaction with it. Windows, Linux, Mac OSX, Android or Unix are some examples.
In many occasions, the operating system has been identified with the complete set of tools and programs of a computer. However, this assimilation is erroneous, since the operating system is a part of the software -not the whole- that makes the rest of the applications work and, in addition, sends instructions to the hardware. In this sense, it is also wrong to think that it is only computers that integrate the operating system, since it is also found in other devices, such as smartphones.
Operation and characteristics of an operating system
The operating system, as we have already mentioned, creates a link between the user, the hardware and the applications, but how does it do this? Let’s imagine that a program wants to access a physical part of the system to develop a function (for example, a word processor, which needs the keyboard to write). Such a connection cannot be established directly between the application and the peripheral, so the operating system has to come into play here.
The operating system understands that the user writes a word and, later, the operating system sends the information to the word processor so that this word is reflected in it. We see that, therefore, the function of the system software has been to link the hardware, the program and the user.
On the other hand, and also in relation to operation, an operating system is characterised by the fact that it starts working immediately after the device is switched on. In addition, it has an important set of drivers that enable rapid compatibility with the hardware.
Finally, it should be added that an operating system offers the user the option of saving programs and data on the computer without the need to resort to external means to do so, and also allows the execution of simultaneous and parallel activities.
What are the functions of an operating system?
So far, with everything explained, we already know what an operating system is and how it works, but we still do not know what this part of the software does.
Therefore, in the following lines, we detail its functions, which are the following:
- It administers the processor and manages the RAM memory space assigned to each program.
- It directs the access of the programs to the peripherals and manages the operation of the hardware.
- It assigns to the applications what they need to work, so it manages the computer tasks that are developed.
- It provides support and maintenance service, being in charge of controlling and improving security, updating versions and adding new utilities, correcting software errors and checking the new peripherals inserted.
- It manages the creation, deletion and access to the files created by the user.
- Establishes communication between the user and the computer.
Components of an operating system
An operating system, in order to perform its functions, consists of the following parts:
- Kernel. It concentrates and develops the basic functions of this part of the software, such as memory management, file control, hardware programming, task staggering or information management.
- File Manager. Records and manages the files created by the user.
- Command interpreter. Communicates the user with the operating system so that the former can gain control of peripherals.
Types of operating systems
The operating systems can be classified into:
- Monotary: they only execute one process at a given time. They cannot attend to another process until it has finished. The most common example is the DOS system, which only attends to one program.
- Multitasking: they perform different processes and operations simultaneously. This is the case, for example, with Windows, Linux or Mac OSX.
- Single-user: in these, only one user can run their programs at the same time. MS-DOS or Windows versions 95 and 98 are some of them.
- Multi-user: two or more users can run their programs at the same time. For example, Unix is a multi-user system.
- Centralized: it uses the resources (memory, CPU, etc.) of a single device. Windows, Linux, Mac OSX or Unix are centralized systems.
- Distributed: uses the resources of different devices at the same time, but acts as a single system, so the user does not know which processor, for example, runs the processes.