Computers
Operating Systems
The operating system is a necessity for the computer to work. It organizes the hardware and software on the computer so they know how to interact with each other. How does it work? The operating system is the first thing the computer sees when you turn it on. It basically tells the other programs you are using when to run and what to do. The operating system is sophisticated enough to be able to prioritize commands and "interrupts" so the user can complete tasks quickly and easily.
In multi-tasking systems like many users utilize, the operating system has to prioritize more commands at the same time, and do it seamlessly, so the user cannot see any slowdown or change in their usage. The CPU can only do one thing at a time, so the operating system has to handle literally thousands of command at a time, and make them all work perfectly. The operating system uses its own memory to help control the processes, which use several other functions in the computer to help make this happen. Processes use registers, stacks, and queues in the operating memory and the CPU to "stack" commands on top of one another so they run successfully in sequence. The operating system uses cycles that use one process and then the other, but this is not apparent to the user. The operating system also makes copies of the registers, stacks, and queues and remembers where one process paused, then reloads all of the registers, stacks, and queues that the next process needs. This process of copying and reloading takes places with each process, and makes the entire computer multi-task so quickly that the user has no idea what is happening.
When the processes switch between each other, the operating system keeps track of what is happening with each one with a "process control block," which contains information about the process and its' status. Each process control block "comes alive" when the process is in use, and is "suspended" when the process is not running. The operating system also manages the memory, such as the cache and the main memory, in the computer and how the CPU uses it. Essentially, the operating system is a traffic cop of sorts, and it uses many other tools in the computer to make sure traffic is always running smoothly.
