What is an Operating System, how many types are there, what are they used for?

What is an operating system?

An operating system is a series of programs that are in charge of managing the different hardware devices of a computer, to allow the interaction of the different applications, which in the end may or may not have interaction with the users.

What is an operating system?
What is an operating system?

What is the purpose of an operating system?


What is the purpose of an operating system?
What is the purpose of an operating system?

The operating system starts automatically when the computer is turned on. The boot functions of the machine’s BIOS are responsible for starting the operating system.

The operating system is responsible for managing access to the hard disk, RAM, video memory, GPU, CPU, CPU interrupts, multimedia devices, bluetooth, wifi, wired ethernet, and input and output devices such as keyboard, mouse, display, USB ports, VGA, HDMI, serial, biometric readers, etc.


Operating system functions


I will now detail the functions of the operating system with each of the components of a computer system:


RAM memory

RAM and virtual memory management
RAM and virtual memory management

The operating system is responsible for the allocation of memory for applications, both at the level of physical memory (RAM), video, and virtual memory (hard disk). The virtual memory is to make use of the hard disk to store data of running applications, so it is slower in processing, compared to applications that use 100% physical memory.

Some computers may have additional RAM memory, known as video memory, which is responsible for more specialized image processing, for example in a 3D animation rendering process, or for image-intensive video games.


Hard disk and file system

Storage Management
Storage Management

As for the hard disk, an operating system is responsible for giving read-write access to the hard disk and its partitions. Conditioned by the system or file table that it manages, for example the NTFS or FAT32 system.

In simple words, the file system is a table of addresses, which allow an operating system to find the physical location of a file or parts of it. So when we delete a file, we do not delete the data, but we delete the address of it in the file table.


CPU Processes


Process Management
Process Management

The operating system is responsible for launching programs or applications to run on a computer.

The processes running on a computer generally have an identifier, are assigned memory, disk space and certain input and output devices.

Here the operating system must give access to the CPU to each of the running programs, so that they can each execute their corresponding actions, generally this is done sequentially but very quickly. In some cases a process can be given priority, so that it is given greater access to the CPU over other processes.

The operating system can then also stop or restart processes, if they have some kind of problem or exception, or by manual request of the user.

There may be cases in which there are programs that run per CPU core, distributing in multiple processing an application, for example for the search of some data in a database, each core can take a subset of data, so that each one gives an answer on its partial information.

As with the video memory, some computers also have a GPU, or graphics processing unit, in charge of handling heavy graphic processes, such as games with 3D animations.


Input and output devices


Gestión de dispositivos de E/S
I/O devices

In relation to input/output (I/O) devices, the operating system must attend to interruptions coming from these devices, in order to receive any type of interaction with the user or with other systems.

When, for example, a letter is pressed on a keyboard, an interrupt is generated in the processor to give priority to the reception of a letter.


Security


Security Management
Security Management

The operating system must also account for permissions to different resources. For example, when a user with administrative permissions is the only one who can install applications, or can save or modify files, as opposed to a standard user who is not allowed to install applications, or delete files.

Also at the security level, permissions to share files, printers, bluetooth devices, network resources, etc. must also be taken into account.

An operating system may allow one or many users connected at the same time, sharing machine resources for each of them.


Network interfaces


Network Management
Network Management

It must also be responsible for managing communication via WiFi or Ethernet network cards, both at the physical level, as well as the protocols that allow such communication, for example TCP/IP V4 o TCP/IP V6.

At the network level, it is also responsible for routing protocols, DNS y firewall, which are other programs that are running on top of the kernel, so at some point I could allow the installation of other components, such as ftp, telnet, ssh servers, proxy, etc.


17 comentarios

  1. Excelente información!!!!, Justo lo que necesitaba repasar para mi examen sobre Fundamentos de Computación, gracias y le pido que siga elaborando materiales tan didáctico para una analfabeta digital como yo…

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