Interrupt is a signal sent to the processor by a software or an hardware, which has a high priority. An interrupt causes the microprocessor to suspend the current thread and provide service to the interrupt. The thread which has been suspended, will continue its execution from the previous state, once the interrupt is serviced.


The program which provides the service to the interrupt is called as Interrupt service routine(ISR) or Interrupt handler. ISR can hold multiple interrupts in a queue, which are organized by the priority of each interrupt. This means that the interrupt with the highest priority will get serviced first and then the rest will be served depending on the priority of each interrupt.

A single computer can only perform one operation at a time, but since the operations can be interrupted, multitasking is archived.


Interrupt can be a:

  • Software Interrupt.
  • Hardware Interrupt.