What is an interrupt and how is it handled?

An interrupt is a signal that temporarily halts normal program execution to handle an event requiring immediate attention. Types: Hardware interrupts (I/O completion, timer), Software interrupts (system calls), Exceptions (divide by zero, page fault). Handling: save current state, determine interrupt source via interrupt vector, execute Interrupt Service Routine (ISR), restore state, resume execution. Interrupts enable asynchronous I/O and multitasking.