Operating system is the program, which usually installed into the computer by a boot program. It manages all other programs in computer. Sometimes it also called as “OS”. These programs also called applications. The application uses the operating system by making requests for services through API (Application Program Interface). Sometimes users can directly use the operating system through GUI (Graphical Users Interface) or command language. Operating system is a program that allows you to work with hardware and software on your computer. Basically, there are two ways to use operating system on your computer. The two ways are as follows: 1. for ex., DOS, you type a text commands and computer give respond to you according to your command. This is called command line operating system. 2. With a GUI (Graphical User Interface) operating system (ex., windows). You relate with the computer through graphical user interface with pictures and buttons by using the mouse and keyboard.
An operating system is software that enables the computer hardware to communicate and function with the computer software. Most desktop or laptops come or preloaded with Microsoft windows. Macintosh computers are loaded with Mac OS. Many computers or servers use the Linux or UNIX operating system. The operating system is the first thing loaded on the computer- without operating system (OS) the computer is useless and we can’t do any functions on it. Now at the moment, operating systems have started to use OS in small computers as well. If we mess with electronic devices, we can see the operating system in many of the devices, which we use every day, from mobile phone to wireless access points. The computer use in these little devices is more powerful and they can easily run operating system and applications of it.
The main aim of the operating system is to organize and control the hardware and software so that the device behaves in a flexible way. All computers does not having operating systems, for ex – the computer that controls the microwave oven in your kitchen, does not need operating system to work because it has only one set of job to do. The most common window operating systems developed by Microsoft. There are other hundreds of other operating system available for special-purpose applications, including manufacturing, robotics, and mainframes and so on.
FUNCTIONS OF OPERATING SYSTEM
As we talk about operating system, it does two things at the simplest level:
It manages the hardware and software resources of the system. In desktop computers these resources such as processors, memory disk space and more.
It provides stable, constant way of applications to deal with the hardware without having the full details of the hardware.
The first task, managing the hardware and software resources and it is very important. The various programs and input methods complete for the attention of the Central Processing Unit (CPU) and demand memory, storage and input/output (I/O) bandwidth for their own purposes. In this capability the operating system plays the good role of a good parent, and making sure that each application gets the necessary resources while playing efficiently with all other applications, as well as it plays good role of husbanding the limited capacity of the system.
The second task is mainly important if there is more than one of a particular type of computer using the operating system. A constant application program interface (API) allows software to write an application on one computer and have a confidence to write a same application on other computer of the same type, even if the sum of the memory or the quantity of storage is different on the two machines. When computer is unique, an operating system can make sure that applications continue to run when hardware upgrades and updates occur. This is because of the operating system not the applications. One of the challenges facing developers is keeping their operating systems flexible enough to run hardware from the thousands of vendors manufacturing computer equipment.
TYPES OF OPERATING SYSTEM
Within the family of operating system, there are four types of operating system based on the types of computers. The categories are:
Real-time operating system (RTOS) – Real time operating system used to control machinery, scientific instruments and industrial system. An RTOS hardly have little user-interface capacity, and no end-user utilities. A very important part of an RTOS is managing the property of the computer so that particular operations executes in same amount of time. In a complex machine, having a part move more quickly just because system resources are available may be just as catastrophic as having it may not move at all because the system is busy.
Single-user, single task – As the name implies, this operating system is designed to manage the computer so that one user can do one thing at a time. The Palm OS for Palm handheld computers is good example of modern single user, single task operating system.
Single-user, multi tasking – This is very popular operating system; most people use this operating system on their desktop and laptop today. Microsoft’s Windows and Apple’s Mac OS are both example of single user, multi tasking operating system. It will let a single user have several programs in operation at same time. For example, it is possible in Windows to write a not in Microsoft word while downloading a file from the internet while printing the text on e-mail message.
Multi- user – A multi user operating system allows many users to take advantage of the computer resources simultaneously. The operating system make sure that the requirements of the various users are balanced, and each of the program they are using has sufficient and separate resources so that the problem with one users doesn’t affect the community of the users. UNIX, VMS and main frame operating systems, such as MVS, are the examples of the operating systems. It’s important to differentiate multi user operating system and single user operating system that support networking. Windows 2000 can support hundreds or thousands of networked users.