what is an operating system and what does it do?

Question

It is for an assignment and i cant think how to word it. I know that Windows, red hat, linix and so on are OS but i dont know how to say what they are and what they do.

Answer 1

They are platforms for which the computer runs on...It is the backbone of the computer...works in the background...

Answer 2

This is a very complex subject and it would take an entire book to explain. Basically there are three parts to the equation here. Hardware, Firmware, and the Operating System. The hardware is the computer parts. They have hardware addresses through which they can be told to do things like input, output, and even program themselves. The firmware is usually called the BIOS. It resides on a chip on the computer board in most cases and it contains a program which was written to it that ties all the hardware information together in a format that the operating system can use to talk to the hardware. An operating system can talk to hardware in two ways. One using BIOS calls and two direct addressing. Direct addressing is almost never used because it would require the hardware of all systems that the operating system ran on to be identical in hardware. This is why the OS makes BIOS calls to interact with the hardware. The OS forms a shell around these calls so the user doesn't have to know how, why, or even what is going on behind the scenes. Most operating systems are modeled by what they call ring-three. This means a user or programmer can not communicate directly with the hardware but must ask the operating system for services when there is a need to communicate with the hardware. This is what the OS API does. The API communicates with the kernel of the OS to make hardware calls. By doing this the OS essential forms an interface by which programs, drivers, and users can use the hardware. The OS is also responsible for memory management, preemption, queuing, process management, resource management (such as channels to a hard drive or memory) Most low level operations occur in the kernel of the OS (some OS such as DOS don't have a kernel) Each process is controlled and given time slices of processor use. If the job is not complete and the time has run out the OS implements a context switch which saves all the process information and puts the process at the end of the queue. When it reaches to front of the queue again the information about the process is then read from its memory location and the process is restarted where it left off. This is how a computer can appear to do many things at once when actually it's only dividing up time slices for each process. This process control, memory management, resource management, and priority are the main functions of the core of the OS. The next layer in most OS is the API in which almost all programs and users request the OS to do things. The OS is essentially the middle man that sits between the BIOS and all programs and program interfaces that users use. It decides what to run when a request is made and when to run it and also what resources to use and how much of a resource the request can have. It also has other functions that could take another two days to type. I hope this helps!

Answer 3

An operating system operates the computer. It has two parts, userpsace and kernel. Userspace is all the programs. The kernel is the part of the os that handles memory management, task scheduling, and in monolithic kernels all other hardware stuff. In microkernels it would contain the device driver api.

Answer 4

The Operating System in simple terms is a set of instructions that a computer uses to tell itself how to "Operate". These instructions are written in a "Code" or "Language" that the computer can understand and use to control and "Operate" all it's various parts such as monitors, keyboards, mouses[sic] ;) sound systems and so on and so on. It also allows the computer to understand the "codes" in the "software" that can be installed on it so that it [and you] can use this software for whatever reason and purpose it is suited to [or sometimes NOT :D ].

Hope this helps...B

Answer 5

An operating system provides a framework for getting all of your computer's parts to work with each other and interface with applications, and provide an interface whereby the user can interact with the programs being run.

Answer 6

There are lots of operating systems. If your computer did not have one, you could not use your computer at all. I have Windows XP. Windows has the BEST operating systems. I cant wait to try out the new WINDOWS VISTA OP.

Answer 7

The OS is basically the driver of a car, it tells the rest of the parts what to do (CPU, Memory, hard drive, software, etc...).