IRQ, short for interrupt request, is a signal sent from a hardware device to the CPU to indicate that the device needs attention. IRQs are used to handle events such as key presses, mouse movements, and network traffic. To check IRQs, you can use the `cat /proc/interrupts` command. This command will print a list of all the IRQs on the system, along with the number of times each IRQ has been triggered.
Checking IRQs can be useful for troubleshooting hardware problems. For example, if you are experiencing problems with your keyboard, you can check the IRQ for the keyboard to see if it is being triggered properly. Knowing IRQ numbers are also critical for understanding hardware architectures for embedded systems or kernel development.