Put your camera in the right place, and make an exposure at the right time.
It is the job of the photographer to organize the world, or permit the world to organize itself, into a picture. A painter can simply move the tree a little bit, and brighten up the boulder a little, and make the mountain loom a little higher, without really even disturbing the scene all that much. The photographer cannot, the photographer simply has to find the right place to put the camera. The early pictorialists, Robinson and Emerson, were pretty big on this. They had a great war over what sorts of post were "legitimate" and what sort were not (is burning and dodging ok or not? Can I fool about with development? What are your thoughts on composites?) They each really disliked the ways the other made pictures, or at any rate Emerson had words for Robinson. Ultimately, though, they agreed on the fundmentals: organize the scene by positioning yourself and waiting for the right moment. If you're moving trees around and re-touching stuff and drawing on the picture, you're not doing photography amy more, you're drawing.
There's nothing wrong with drawing, of course. But it's not photography.
Then we see the later pictorialists, who were frustrated painters, scribbling all over everything.
Then we see f/64 and straight photography, which circles right back around to the fundamental act.
Things might be permanently fractured now, since everyone's a photographer. Still, we see in fits and starts "anti-Photoshop" people, who get shouted down a lot, but who are as near as I can tell just trying to go around the cycle to the beginning again. Certainly it is rare in these days to find a well made picture that does not come with some caveats like "I cloned out the sign and the other thing" which arguably isn't photography at all. When we're fixing stuff like that in post, removing this thing and that, arguably we've failed in the fundamental act. If you didn't like the sign, why on earth did you stand where you did? Stand somewhere else and take a better picture.
I say all this as a guy who scribbles all over his pictures. I don't claim that the fundamental act is the only way to make a picture because, manifestly, it is not. The point is, that's what photography boils down to. Almost nobody does pure photography any more. Perhaps nobody ever did. Certainly there are degrees, veritable multi-dimensional continua of what can be and is done.
Nontheless, photography in its essence consists of standing in the right place, and pressing the button at the right moment.