operating system
The operating system is interacting with the computer hardware human intermediary. Is actually a set of programs focused on this group of programs is that all hardware and drive all activities in computer systems management. The core function is to allow the CPU can start determination value logical AND operation, so that memory can start loading / read data and program codes, so that the hard disk may be read start, so that the card can begin transmitting data, all the peripheral hardware ready to run and many more.
The operating system is a computer system essential foundation system software, which is running the application, and user support operations necessary basic environment is the core computer system.
Role of the operating system is to manage and control various computer hardware and software resources, such as CPU usage, memory usage is detected, the system remaining disk space, while the supply and demand of the system resource management priorities.
The operating system may also control the device input, output and operating a network with management and file systems. At the same time, it is responsible for the management of computer systems in various types of software resources. Such as installing, operating environment and other kinds of application software settings. 
Operating system is used in the delivery system software information between the user and the computer hardware. Results operating system upon receiving a user input, which is transmitted to the computer system for processing core hardware, computer hardware and then returned to the user process.
Currently PC (Intel x86 series) on the more common computer operating systems: Linux, Windows, DOS, Unix and so on.