Abbreviated as APIC, an Advanced Programmable Interrupt Controller is a PIC used to extend the number of IRQs available, has more available interrupt lines that a typical PIC and also supports distributed CPUs. APIC must be implemented on the motherboard and also supported by the operating system. APIC differs from PIC as it offers multiple APICs on a motherboard connected via a bus system. The CPU has a LOCAL APIC and the motherboard has at least one I/OAPIC.