Or, if you prefer, Still Photography isn't the same thing as Motion Photography. I don't care much how we name the things, I care that we stop muddling them together.
There is a depressing tendency to treat these two under more or less the same umbrella, to suppose that motion photography and still photography are more or less two variants of the same thing, or that one is a special case of the other, or whatever. Anyone who does one can probably do the other, and (especially) a critic of one ought to be able to criticize the other just about as well. The skills in various cases should pretty much translate straight across.
Technically, sure. The equipment used to make these things is similar, and shares some of the same technical details. They are 2 dimensional, visual.. I am running out of similarities.
In every other way, they have almost nothing to do with one another. Still photography more resembles painting than it does motion photography. You could make a case that it more closely resembles sculpture than it does motion photography.
Consider the differences between still photography and motion.
They are made completely differently. In one case you are looking for (and recording) one or more instants, and in the other you are looking for (and recording) stretches of time. This changes how you manage the set and the people (if any) on it, how you move, how you hold the camera, how you light. Let us set aside entirely the considerations of sound, although sound is hugely important in modern motion photography.
They are consumed completely differently. A photograph is consumed on my schedule, a video on yours. This is an oft-overlooked difference, and it is huge. Just sit and ponder that for a moment. I can look at a picture for a moment or an hour, if I like. A video I cannot. I can pause it, repeat it, rewind a bit, perhaps play it again in slow motion, but ultimately one frame will follow the next more or less on the artist's schedule, or the piece won't make any sense.
They behave completely differently. A photograph (or painting, or sculpture) represents a single moment, a facet, a single slice of something. A group of them represents several slices. The work demands that the viewer construct whatever it is that these are supposed to fit in to. Video gives us that world, still constrained visually, but not temporally. You can argue that film is just a whole bunch of slices, but you are being facetious and you know it. The perception of video is of continuous time, that's the point, and as such it's different.
Roland Barthes was a bloviating idiot, but he got this part right. Motion photography is almost completely unrelated to still photography.