Many lights have a level of adjustability as an additional feature, for example spotlights can point in various directions to position light where it's needed. Other adjustable light may be pendants that can be raised or lowered by a pulley or retractable cord, these are Rise and Fall Lights. But often height adjustable lights can be shortened to fit your chosen height but once shorted the'll be fixed in that position.
Check out the rise and fall lighting perfect above tables.