What's Par lamp for?

There are many kinds of led par lamp in the market now! Par lamp Is actually a power vacuum within the gas source, column: There are neon ordinary bulbs, fluorescent tubes in a argon gas, lighting a small lamp cup lamp beads in there, the name of these gases from the first sight to understand, family of halogen elements are, of course, because some high cost of gas, the system made the cost to be considered a civilian.