Operating system – It is system software which controls the hardware and software resources of the computer and offers common services for computer programs.
The operating system is used as a midway between programs and the computer hardware for hardware functions such as input and output memory allocation. The operating system is present in computer, mobile phones and video game consoles to supercomputers and web servers.
There are some different operating systems can be used for different purposes. Several operating systems are used for normal things on personal computers and others are used for particular work.
An operating system has several works in which entirely programs can use the CPU, system memory, displays, input devices, and other hardware. Operating system also talks to other computers or devices on a network. There are several operating systems such as macOS, Linux, and Microsoft Windows.
At present, Microsoft Windows is the leading and popular operating system. The share in market of Microsoft Windows is about 82.74 percent which is at the top. The other operating system such as Apple.Inc made macOS is second one share in market at about 13.23 percent and Linux is at 1.57 percent. Android is also very main and popular and operating system in smartphones which is about 87.5 percent with growth year of around 10.3 percent in each year.
Types of operating system – There are several operating systems which are discussed below
1. Single– and multi–tasking – A single-tasking system allows only one program in one time whereas a multi-tasking operating system can operate more than one program. Multi-tasking may be divided into two types
(a) Preemptive multitasking – In this type of multitasking operating system, the operating system shares the CPU time and offers a slot of each of the programs such as Solaris, Linux and Amiga operating systems are preemptive multitasking.
(b) Cooperative multitasking – In this system, it depends upon on each method to deliver time to the other processes in a well-defined manner. The example is 16-bit versions of Microsoft Windows used cooperative multi-tasking.
2. Single– and multi–user – It allows several programs to operate. A multi-user operating system used the basic theory of multi-tasking with good services which identify procedures and resources, such as disk space which is working with multiple users, and the system allows to several users to interact with the system in the same time.
3. Time–sharing – In this system, it also allows multiple users for distribution of processor time, mass storage, printing, and other resources
4. Distributed – A distributed operating system controls a collection of separate computers and makes them seem to be a single computer. The growth of networked computers can be connected and converse with each other to give rise to distributed computing. Distributed computations supported more than one machine. When a computer works in teamwork, they form a distributed system.
5. Embedded – These Operating Systems are manufactured which can be used in embedded computer systems. They are made to run on small machines such as PDAs with less independence. They are capable to run with a restricted number of resources. They are very compact and tremendously efficient by design such as Windows CE and Minix 3 are embedded operating systems.
6. Library – It is an operating system in which the service offers, such as networking, are provided in the form of libraries and collected with the application and configuration code to make a unikernel. Unikernel is a particular, single address space, machine image which can be installed to cloud or embedded environments.