The Advanced Programmable Interrupt Controller
(APIC) is an interrupt management component. It has considerably more outputs than the classic Programmable Interrupt Controller (PIC), a more complex priority scheme and better interrupt management with more interrupt lines.
The APIC component only makes sense if the computing unit consists of several processors or processor cores. It directly intervenes in the functions of the central processing unit (CPU) and those of the chipset by communicating the interrupt requests of several I/O APICs to the local APICs of the processor core.