The operating system (OS) is what runs your whole computer. Without it, your computer would just be a stack of devices that have no idea what to do. This is because the operating system performs the nitty gritty details that are needed for your computer to successfully run the applications that you use every day- applications like word documents, games, and spreadsheets!
A computer's operating system performs a couple of basic tasks:
However, these single-tasking operating systems are pretty much obsolete now, as new technology has made it possible for us to run more than one program at a time. As a matter of fact, right now I have open Microsoft Encarta Encyclopedia, a word processor, and an Internet browser! You might be wondering how this is possible, if I have just stated that only one task could be performed at a time. Well, this is all possible because of the operating system.
Although different operating systems will deal with the problem of running multiple applications in different ways, they all essentially have the same basic idea. The central processing unit must switch between the multiple applications that are being used several thousand times a second in order to make it appear as if they are all running simultaneously!
First, one of the programs is run. The CPU runs this program for an allotted amount of time. Once time is up, the operating system will make a note of where the program left off when it was paused. It will then determine which program should be run next. The operating system will load this program and let it run for the allotted amount of time, before moving on to the next application. Once it goes through all of the applications that are being used, it will return to the first one! The amazing thing is the speed at which the operating system works! It can do all of this thousands of times a second!
2. Memory and Storage Management:
The operating system gives the applications that are currently run a certain amount of space in the computer's random-access memory (RAM). But what happens when the computer runs out of RAM? Since CPUs can only perform one task at a time, much of the RAM is not used at a given time. This is because only one application is actually being run at once, so the memory taken up by the other applications are not in use. Because of this, some of the data stored in the RAM can be transferred to the hard disk until that application is being used. This is called Virtual Memory Management.
3. Device Management:
4. User Interface:
Well, the computer's user interface
is the software that lets you and your computer pass information to each
other. There are many different types of user interfaces.
Some user interfaces are text oriented. The user has to type in data in the form of a letter, word, or other type of command.
The modern user interface that is found in almost all computers today is called Graphical User Interface, or GUI. I'd bet you anything that the computer you are using to read this article uses GUI. This is a type of "point-and-click" interface. There are pictures and icons that represent things like the trashcan, certain applications, files, etc. It is designed to look like your desktop. There are folders that represent different files and documents you might have created; there is a trashcan for files and applications that you wish to get rid of; there is even a calculator! You can select certain applications and programs by just clicking on it with your mouse! This type of interface is user-friendly and extremely easy to use!
Some of the most common types of operating systems in use today in computers today are:
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