Is there a difference between SLR online shooting line and ordinary data line?

It makes no difference whether the interfaces are the same or not.

Essentially, it is a USB cable and a data transmission medium.

SingleLensReflexCamera, also known as SLR camera, refers to a camera that uses a single lens, through which light shines on the reflector and takes a view through reflection. The so-called "single lens" means that the photographic exposure light path and the framing light path * * * use one lens, unlike the paraxial camera or the double-reflex camera, the framing light path has an independent lens. "Reflection" means that the plane mirror in the camera separates the two optical paths.