An interrupt is a signal sent to the processor that immediately stops the execution of the current process to attend to a specific condition that needs to be handled right away. This mechanism allows a computer to deal with events as they occur, which is crucial for real-time processing.

Interrupts can be categorized into two main types:

1. Software Interrupts: These are generated by software or the system rather than hardware. They are also known as traps or exceptions and are used by the operating system or system services to perform specific functions or respond to error conditions.
2. Hardware Interrupts: These are signals sent from hardware devices (like keyboards, mice, network cards, etc.) to the processor. They inform the processor that the device needs immediate attention, such as when new data has arrived or an operation has completed.