Introduction to Operating System
The Important Elements of an Operating System
Usually the operating system has some crucial key elements. The first element is known as the technical level or layer which is responsible for carrying the basic operations of the hardware. The second important element of the operating system is referred to as the file system. File system is responsible for logically arranging the files. The third element of the operating system is directly linked to the users operations and is known as command language. Command language guides the users to run different programs and manipulate their tasks. These are the key elements of operating systems however an operating system is also comprised of compilers, text editors and debuggers. This helps in smooth functioning of the system and also ensures the security of the system. Whenever we make a request it travels to the operating system in order to seek OS permission to use the resources of the computers. It is due to this reason that operating system is often considered as the care taker of the PC.
Types of Operating Systems
There are further sub categories of operating system depending upon the number of tasks they are able to perform. Moreover operating system can also be classified on deciding how many users can use it a t a time. These categories include multi user, single task, single user and multi task. Let us analyze some of the examples of the operating systems. Windows 3X is a single user single processor able to perform simultaneous tasks. MS DOS is a perfect example of single task single processor and single user operating system. UNIX is a multi task and multi user operating system. Windows 2000 is a multi task and multi user operating system having number of processors. Amiga DOS is a single user multi task and single processor operating system. VMS and hline MTS are multi user, multi task but single processor operating system. NT is the only processor which is able to serve single and multi users and are able to perform multiple tasks while they work on many processors. Macintosh system seven is a single user but quasi tasking OS which is capable to operate on a single processor. Quasi tasking allows the user to run several user applications alongside or simultaneously
Working of the Operating System
If we take the computer system as whole then operating system is residing at the third layer of the system. Hardware is at the first layer, second layer contains the drivers, the third layer possesses OS and the fourth layer is the application layer. OS creates a link between the user and the softwares. Whenever, a user runs a set of instructions or a program to send a message to any hardware device. This message is sent to the operating system first and the OS runs the programs by making use of its drivers. Drivers facilitate the working of the system. Without drivers it is necessary for the programs to communicate directly with the intended hardware devices. Operating system is therefore helpful in simplifying the resource management task for the users. It helps the end user to overcome the complexity of dealing directly with low level machine languages.