IRQ is called Interrupt Request and the devices use this to get an ID to use processor resources. I would like to quote an example here and that is, when you press a key on your keyboard it sends a signal to the processor via an IRQ channel to let it know that it needs to process some data and in response processor spare some resources to process the request. There can be more than one scenarios where IRQ conflicts can occur when new hardware is installed or reconfigured. For example, it can cause problems if you have your mouse on COM 1 and a modem on COM 3. let me share a list of IRQs;
