• The operating system is the most important program that is on a computer. The operating system basically runs the computer and allows other programs to run as well. The operating system does all the basic things that a computer needs to do, such as recognizing inputs from the mouse or the keyboard. It keeps track of where all the files are on the computer. It allocates resources to the various programs that are running and it prevents unauthorized access to the computer.
• The most popular operating system today is Microsoft's Windows operating system. Macintosh computers have their own operating system, the most recent of which is called Mac OS X. There are also open source operating systems such as Linux.
• An operating system, abbreviated OS, is a product, software type, that is part of a system, equipment or computerized equipment, which deals with management and coordination of its activities. The computerized system may be a computer, a workstation, a server, a PC, a notebook, a smartphone, a road navigation device or another system with "intelligence" of its own. The operating system plays the role of host for all applications running on the equipment (hardware).

Operating system functions

To act as interface between hardware and users, an operating system must be able perform the following functions:

1. Enabling startup application programs. Thus, the operating system must have:
2. A text editor
3. A translator
4. An editor of links
5. The allocation of resources needed to execute programs is done by identifying: the programs that are running, the need for memory, peripheral devices and data protection requirements.
6. Facilities for data compression, sorting, mixing, cataloging and maintenance of libraries, through utility programs available.
7. Plan implementation works according to certain criteria, for efficient use of central processing unit.
8. Assisting implementation of programs through computer-user communication system, at both hardware and software level.

Examples of operating systems: BS2000, BS3000, DOS, PC-DOS, MS-DOS, LINUX, SOLARIS, MAC OS, UNIX, WINDOWS

• An operating system (OS) is a set of computer program that manages the hardware and software resources of a computer.
• At the foundation of all system software, the OS performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking, and managing files.
• It also may provide a graphical user interface for higher level functions. Various services performed by operating systems are discussed below. Process management:
• It deals with running multiple processes. Most operating system allow a process to be assigned a priority which affects its allocation of CPU time.
• Interactive operating systems also employ some level of feedback in which the task with which the user is working receives higher priority.
• In many systems there is a background process which runs when no other process is waiting for the CPU.

Memory management:

• The memory manager in an OS coordinates the memories by tracking which one is available, which is to be allocated or deallocated and how to swap between the main memory and secondary memories.
• The operating system tracks all memory used by each process so that when a process terminates, all memory used by that process will be available for other processes.
• Disk and file systems: Operating systems have a variety of native file systems that controls the creation, deletion, and access of files of data and programs.

Networking:

• Most current operating systems are capable of using the TCP/IP networking protocols. This means that one system can appear on a network of the other and share resources such as files, printers, and scanners.
• Many operating systems also support one or more vendor-specific legacy networking protocols as well.

Security:

Most operating systems include some level of security.

Device drivers:

• A device driver is a specific type of computer software developed to allow interaction with hardware devices.
• Typically this constitutes an interface for communicating with the device, through the specific computer bus or communications subsystem that the hardware is connected to, providing commands to and/or receiving data from the device, and on the other end, the requisite interfaces to the operating system and software applications.