||Where or what is the limelight as opposed to the spotlight?|
Limelight is a term from the late 19th/early twentieth century, describing a particular type of electric light used to produce lots of focused illumination. It was a type of arc lamp, with two calcium-lime electrodes held in close proximity of each other. When voltage was applied, a heavy arc of current was produced between them. Effective but dangerous. Such "limelights" were used in theaters before common incandescent "spotlight" lamps replaced them.|
Thus an actor, and by extension, any celebrity, was said to be in the limelight.
It's a hold-over word.