Today, when I was taking a wedding photo, I met a photographer and pointed a lamp at the roof of the studio. What kind of lamp is this? What's the role?

Fill light lamp: the so-called fill light lamp is a kind of lamp used to compensate some equipment or plants for lack of light. At present, there are usually three kinds of fill light, one is camera greenhouse fill light (also called plant fill light), photography fill light (also called camera fill light) and license plate fill light (also called white light).