IRQ

Abbreviation of interrupt request line, and pronounced I-R-Q. IRQs are hardware lines over which devices can send interrupt signals to the microprocessor. When you add a new device to a PC, you sometimes need to set its IRQ number by setting a DIP switch. This specifies which interrupt line the device may use. IRQ conflicts used to be a common problem when adding expansion boards, but the Plug-and-Play specification has removed this headache in most cases.

The hardware lines used py PC peripherals such as printer or modem to communicate to the microprocessor that the device is ready to send or receive data.IRQ (Interrupt Request )