What is an Operating System?

In this article we’ll give basics of an operating systems tasks and usage. So, what is the operating system?

Definition Of The Operating System

An operating system (OS) is a software package which acts as an interface between user and a hardware, it’s set of programs which control use of resources (CPU, RAM, HDD…), program execution, memory allocation and data management.

Main objective of the OS is to enable:

• • Simpler use of the system (so that user doesn’t have to worry about hardware specificities)
  • More efficient use of system’s resources

Tasks Of The Operating System

Operating systems tasks are:

• • Process management – A process is a program in running state. OS has to: perform tasks of creation and termination of user’s and system’s processes, delaying, interrupting and reactivating processes, synchronization, communication between processes and solving deadlocks.
  • Random access memory (RAM) management – OS has to: keep track which RAM parts are currently occupied by which process/user; allocate and free up memory space as needed; decide to which process to allocate RAM space that is currently free;
  • Secondary memory (storage) management – OS has to: manage free memory space, allocate memory, manage secondary memory access requests.
  • Input/Output management – Input can be: keyboard, mouse, … Output can be: Screen, file, …
  • File management – OS has to do basic operations on files (such as: create, delete, open, close, read, write), organize access to files and directories
  • Security of the system – OS has to do authorization and authentication of the users
  • Error detection and handling
  • Enabling network operation
  • Interpretation and execution of user commands

There are many cases where operating systems are essential for devices to work, most common examples are desktop computers, laptops, mobile phones, tablets, servers, network equipment, …

On desktop computers/laptops mostly Windows or Linux are used. (macOS on Mac computers)
Mobile phones and tablets mostly use Android. (iOS on iPhones)
On network equipment OS depends on vendor some examples are: Cisco IOS, Junos (Juniper), RouterOS (MikroTik)

Many of operating systems use Linux as their base, for example Android or RouterOS.

Worldwide market share of desktop operating systems is as follows:

Source: StatCounter Global Stats – OS Market Share

Worldwide market share of mobile operating systems is as follows:

Source: StatCounter Global Stats – OS Market Share