Services of Operating System

Services of Operating System

Operating system services are divided into two categories

a. Services that are helpful for the user

b. Services that ensure efficient operations of the system itself. 

Services helpful for the User

• Program execution: The Operating System is responsible for execution of all types of programs whether it be user programs or system programs. OS loads a program into memory and run that program. The program must be able end its execution either normally or my raising an execption or error.  It uses various resources available for the efficient running of all types of programs

• I/O Operations: The main job of a computer is I/O. A running program may require I/O. The user usually cannot control I/O directly. Therefore, the operating system manages and control I/O operations and I/O device. 

• File System Manipulation: The Operating System is responsible for making of decisions regarding the storage of all types of data or files, i.e, floppy disk/hard disk/pen drive, etc. The Operating System decides as how should the data should be manipulated and stored.

• Communication: Computer systems allow multiple programs to be loaded into memory and executed concurrently. Processes can communicate with each other to exchange data and information. The communicating process may be running on same computer or on different computer system connected via network. Operating system move information between processes either via shared memory or through message passing.  

• Error Detection: A user program may give error like access to illegal memory space, division by zero. Similarly error may occur in CPU or other hardware device. There may be connection failure. Therefore, OS take necessary actions, correct errors  and avoid the malfunctioning of computer system.

Services helpful for the System

• Resource Allocation: The main objective of multi-programming is to maximize CPU utilization by running some process all the time. When one process has to wait for say I/0, the OS takes the CPU from that process and allocate to another process. This is known as scheduling. All the resources are scheduled before use and therefore it is the primary function of operating system. 

• Accounting: Operating  system  keep  track of user process and user activities in terms of how much and what kind of computer resources are used. This recorded information is used as resource  usage statistics for a particular user or group of user.

• Protection and Security: Operating system ensures that all access to the system resources are controlled and access of outsiders is prohibited.  The operating system uses password protection to protect user data and similar other techniques. it also prevents unauthorized access to programs and user data.