The digital sign board is a type of modernization, making use of electronic media, of traditional types of communicating with indications and also articles. An electronic sign board differentiates itself in the capacity for fast updates and even dynamic, real-time communication. But conceptually it is no different from the billboard, the marquee, and similar forms of signage.
These digital signboard precursors go back to well over a hundred years. They remained in analog form, naturally, and their messages were reasonably fixed, continuing to be unchanged for possibly a week, maybe a month, or probably for years. They were mostly textual, however typically consisted of some type of images, specifically if they were made use of for advertising.