Highlighter is a marker pen produced in recent years. It uses thicker and lighter ink to cover key parts for marking. After marking, it will not block the text at a glance. The fluorescent pen has fluorescent agent. When it encounters ultraviolet light (sunlight, fluorescent lamp and mercury lamp are more), it will produce fluorescent effect and emit white light, which makes the color look dazzling fluorescent. It is often used for office study.