Photography (drawing with light) is quite amazing and wonderful. It is also quite unlike its—apparently!—close cousin, film; or that other relation, painting.
Think about it. A photo is a capture of the visual aspects of a unique instant in time, from a unique perspective and taken under circumstances that will never ever be repeated in the entire history of the universe.
This is an amazing power. There's nothing else that can do exactly that. Nothing else can freeze time and reality in the same way. Paintings will never do it because they only freeze the vision of the painter, not of the true configuration of light and shadow that paint the photo through the brush that is the lens onto the canvas, which is the film or sensor array. Even 'enhanced' photos, even if they're mono-chromatized, still have a connection to reality and that instant of capture that no painting will ever have.
There may come a point where post-processing moves them beyond the point of having a real 'relationship' with the original capture, but you've got to go quite a long way to get to there. And a lot of what's passed off as photographic 'art' is well beyond the vision I outlined in the previous paragraph. But that's not the photography I'm talking about; the kind that means something to me.
A popular trope about photos is that they 'tell stories'. You can read this everywhere, and you will hear it from even the most seasoned and sage of photographers.
But here's the truth: A photo doesn't tell a story. It can't. And—paradoxically and unintuitively perhaps—in that very limitation lies its power. That's because 'stories'—narratives, tales, whatever you want to call it—are sequences of events, either true or imagined—or a combination of both; sequences of connected instances, distributed over a period of time and space and connected in some meaningful way.
A photo on the other hand is a frozen instant. Photos may be sequential frozen instants that together make up a collection of frozen story snapshots. If they are spaced closely enough together so that we can't them apart, they may appear as a continuous sequence, capable of evoking the illusion of a narrative; that is, a film. But in film as in life, it's time and sequence that creates 'narrative' out of reality.
The individual frames, known in the trade as 'stills', help us to understand what a photo is: a solitary frozen instant in the time-sequence of the story. Not something that 'tells' a story, but which may, depending on its quality, actually stimulate the viewer to supply, through their own imagination—and, in the instance of a movie, possibly some knowledge of the movie-story itself—a narrative of the imagined past that came before that still-frame and the future that follows, or the many futures that may follow, it.
So, though a photo appears to 'tell a story' it doesn't—though it may, if it is of sufficient quality, stimulate one's imagination to supply an accompanying story. And this is why people often think the photo 'tells' it. It doesn't; it just stimulates. But that very stimulation is what makes photography—and its artistic cousins; mainly non-abstract painting and sculpture—into such amazing tools to trigger the creative-imaginative process in people themselves: because we have to supply the story, instead of having it served up to us.
Photos may also trigger memories and sequences of memories. But as we now know, memories themselves are creative and re-constructive; and the power of photos to re-construct those memories, and occasionally fabricate memories of events that never happened, has been demonstrated through extensive psychological experiments.
Freezing time by drawing with light. Locking a unique instant down forever. Whether it is a loved one smiling, a wave breaking, the sun setting behind a mountain or tree, the galaxy hovering above, a particle spiraling in a magnetic field after a subatomic collision. Memories, emotions, science.
This is the essence of a photo.
More about photography vs. video in the context of events like weddings, can be found here.