Operating System Services

1. Program execution – system capability to load a program into memory and to run it
2. I/O operations – since user programs cannot execute I/O operations directly, the operating system must provide some means to perform I/On
3. File-system manipulation – program capability to read, write, create, and delete files
4. Communications – exchange of information between processes executing either on the same computer or on different systems tied together by a network. Implemented via shared memory or message passing
5. Error detection – ensure correct computing by detecting errors in the CPU and memory hardware, in I/O devices, or in user program