IBM PC compatibles, commonly refered as PC, are computers compatible with the the original IBM PC released in 1981. As of today, amost all personnal computers are PC compatibles.
They are based on the x86 microprocessor familied created by Intel. Many operating systems were designed for PC compatibles. It's a software layer that allow a friendly use of the computer functionnalities, such as playing videogames.
This entry is related to the Windows operating system, created by Microsoft in 1985.