Walk past any screen doing its job and you do not think about the screen. You think about what it is showing: the wait time, the announcement, the safety reminder, the figure on the board that ticked up a moment ago. That is content, and it is the entire point.
Everything else in Screenly exists to serve it. The device, the software, the playlists, the schedules: all of it is machinery for getting one thing right, which is what appears in front of a person at a given moment. A signage system can be technically flawless and still fail, if the content on the screen is wrong, out of date, or ignored.
Content is also the most open-ended part of the system. It can be a single image that stays up for a month. It can be a video that loops all day. It can be a live dashboard that has not looked the same for two minutes running. Signage treats all of these as content, because from the screen’s point of view they are the same kind of thing: something to show an audience.
That breadth is what sets digital signage apart from a printed poster. A poster says one thing until someone takes it down. A screen can say one thing now and another in an hour, can respond to the time of day or the data behind it, and can be changed across a hundred locations from a single desk. The message is no longer stuck to the surface it appears on.
So it helps to think of content as the message first and the file second. The format matters, but what matters more is what you are trying to say, who needs to see it, and how current it has to be. The rest of these pages are about the shapes that message can take.