The Operating System provides some services to programs and to the users of those programs, in order to make programming task easier.
Although services provided by Operating System differ from one Operating System to another, there are some Services that are provided by almost every Operating System.
Services provided by Operating System are
the services provided by the operating system can be categorized into following ways
1. Program Execution.
The Operating System should be able to load a program into memory and execute it.
2. I/O Devices.
Normally, a user program cannot execute I/O operations directly. So when a running program needs an I/O, the Operating System should be able to fulfill the need for that program.
3. File System.
Programs need to read and write files. Similarly, new files can be created and unwanted existing files are deleted. Operating System should be able to manage the activities related to files.
4. Communication.
Sometimes, programs need to exchange information with each other. Exchange of information can be implemented using a Shared Memory (Same Machines) or Message Passing in the form of Packets (On a Network). So, Operating System should be able to communicate between programs.
5. Error Detection.
The Operating System should always be aware of possible errors. Errors occur due to Hardware i.e. CPU, Memory or I/O Devices etc or due to Software i.e. User Programs etc. The Operating System should take necessary steps to ensure correct and constant computing.
Following are the Services that do not help User Programs but are used for Sharing Computer Resources and giving Reliability/Stability and Efficiency.
6. Resource Allocation.
Operating System is the manager of resources and when resources are requested by different users at the same time, then Operating System Allocates and Deallocates these resources to many Users/Programs in an efficient manner.
7. Accounting.
Accounting is used for two purposes.
i) To keep track of resources, i.e. which resources are used by which users so that they can be billed.
ii) Usage Statistics of resources may be a valuable tool for researchers in order to reconfigure the system for improving Computing Services.
8. Protection & Security.
services provided by the operating system for protection and security
Protection & Security is a very important service provided by Operating System in Multi-user Environment.
Protection ensures that all access to System Resources is controlled and several jobs executed simultaneously should not interfere with each other.
Security ensures that outsiders will not gain access to the system. Security is implemented for users to specify passwords in order to gain access to System Resources.
