Halogen bulbs are incandescent bulbs. Halogen bulbs, however, are filled with a special gas that actually rebuilds the filament and provides longer average lifespan than normal incandescent bulbs. The PAR series of halogen bulbs are flood shaped with heavy, thick glass that is common in many medium to large sized halogen bulbs. PAR stands for parabolic aluminized reflector. These types of bulbs will provide you with a higher light output, a more white-colored light (a higher color temperature - 3000K-3200K), and longer life than normal R or BR reflectors.
The PAR64 bulbs are specialized bulbs that are not used in everyday applications. They are meant for high wattage-high lumen applications and are often labeled as Projector/Stage/Theater lighting. That isn’t the only use, of course. In fact, one of the most common places to see these bulbs is at an airfield on airplanes. You can tell what kind of PAR lamp you have by measuring the distance across the widest point of the bulb. The number after 'PAR' shows the number of eighths of an inch in diameter the bulb is. Therefore, PAR64 lamps are 8 inches across.
Sylvania, Philips, and GE offer PAR64 lamps. They have bases called GX16D, or External Mogul End Prong; the best way to describe how this base type works is to say you simple push the bulb into the socket, and it fits into the fixture and stays in place without twisting. The base resembles an electrical 2-prong plug found on normal, everyday items.
You can get the bulb in several beam spreads. The names for the spreads are as follows: VNSP (very narrow spot - FFN), NSP (narrow spot - EXC), SP (spot - EXD), MFL (medium flood - FFR and EXE), and WFL (wide flood - FFS and EXG).
PAR64 bulbs are available in various voltage and wattage combinations. You can find them in 1000 watt, 200 watt, 600 watt, 500 watt, and 120 watt versions. Voltages range as follows: 6 volt, 28 volt, 120 volt, 130 volt, 230 volt, and 240 volt.
It is clear that this type of bulb is highly specialized and it would be accurate to say that most people will travel through life without ever observing their existence. Thanks to their size, odd base, and distinct voltage offerings, the bulbs are not typical in your local lighting shop. Still, there is a place for the PAR64; since they are halogen the items shown under this light will appear more brilliant and will display a brilliant color than under normal incandescent bulbs. And the lumen output is at a level that most other bulbs do not match.