The are many uses for a high-intensity discharge lamp light for those that use one. The main use for the high-intensity discharge lamp lights is to cover a large area that needs light.

Methane.

High-intensity discharge

high intensity discharge

There are tubular incandescent lamps for high-intensity fixtures, such as the FCM lamp. However, if it's more than a few inches long and appears white or "cloudy", it's almost certainly a fluorescent light instead. (If it's clear, then it's likely a gas discharge lamp, such as a neon lamp.)