An exclusive video game is a game only released on one platform. Often these are First Party games directly from the hardware manufacturer. A new term, the so called "console-exclusive" games, was introduced mainly because many Xbox and Xbox 360 products are also (often later) releaed on the PC. Some people argue now, that these titles are somewhat exclusive too - console eclusive as they are only on one console - because the PC is not a direct competitor to the consoles. You could say the same with handheld and console games.