While there are many individual segments of a complete computer system that could be considered "system resources," there are generally four major resource types, all viewable and configurable in Device Manager:
- Interrupt Requests (IRQ) Lines
- Direct Memory Access (DMA) Channels
- Input/Output (I/O) Port Addresses
- Memory Address Ranges
System resources can not usually be used by more than one piece of hardware. The major exception are IRQs which can, in certain situations, be shared among multiple devices.
Windows automatically assigns system resources to hardware devices if the devices are Plug and Play compliant. Nearly all devices, and certainly all commonly available computer hardware devices available today, are Plug and Play compliant.