
Recessed lighting fixtures are just what they sound like: light fixtures that fit neatly into your ceiling, casting light downwards while the fixture itself remains relatively hidden.
Basic recessed lighting fixtures have two main parts: a housing unit, or can, to hold the bulb and a circular trim piece to neaten the appearance of the hole cut into the ceiling for the housing.
While regular housing recessed fixtures are meant to be installed at the time of construction, remodel housing fixtures are available for those who want to install them in existing ceilings. Also available are thermally protected housing fixtures for ceilings with insulation layers that may burn if next to unprotected, regular housing.
Trims also vary; some fit flush to the ceiling, leaving the tip of the fixture's bulb exposed, while other trims are referred to as "eyeball" trims because they allow the bulb to swivel.