Light Bulb. This is a Linear halogen tube bulb, it's often used in uplighters, floodlights and ceiling lighting. It's suitable for outdoor use in a closed light fitting.
The high wattage makes it by no means energy saving, or efficient. It's best used for short periods, such as security lights activated by PIR sensors, and other situations where you need instant light. In these cases more efficient sources of light might not be suitable due to warm up times etc.
Lights that are on for long periods of time e.g. main room lights, or outdoor lights that are on all night, should ideally use a more efficient source of light. As with all linear halogen lamps, while installing the lamp it's important not to touch the glass part of the lamp with bare skin as the natural oils from your skin can cause the lamp to fail prematurely.
If you do touch the lamp, then you should use alcohol to remove the oils from the glass.