Resource allocation

1. When there are multiple users or multiple jobs running at the same time, resources must be allocated to each of them.
2. The operating system manages many different types of resources.
3. Some (such as CPU cycles, main memory, and file storage) may have special allocation codes, whereas others (such as I/O devices) may have much more general request and release codes. For instance, in determining how best to use the CPU, operating systems have CPU-scheduling routines that take into account the speed of the CPU, the jobs that must be executed, the number of registers available, and other factors.
4. There may also be routines to allocate printers, USB storage drives, and other peripheral devices.