Digital Art can be a funny beast. Everyone will have their own definition. I suppose in it's most basic form it ios creating Art using digital tools. Therefore it could range from digital photography through to photographic manipulation and composition. It also includes artwork created from scratch using digital tools - no photography involved.
For me, it usually starts with photography. Whether as a base image or as a reference. And I have usually have taken that image. That's just me - it's how i like to work. I like to start with my own photographs (how else can I justify the expensive camera to my wife :-))
Photography - Digital Art
But then the world literally opens up. I could then do some basic adjustments and leave it as a digital photograph. A photograph is still digital art to me. Give five photographers the same image and you will get 5 interpretations. But to most of the world this is classed as Photography. A fairly faithful representation of a place in time.
Digital Art - Photography (A subtle Difference)
Then we get to the next level where an image is definitely processed with no respect to how faithful it is to the original image. It is a more artistic representation. Other images may be combined. Layers of textures may be added and blended. The image may be made to look more like a painting.
Digitally Created Art
And then finally we get to art that is completely created from scratch digitally. For some, this will involve sketching and painting in a program like Photoshop or Corel Painter. For others, including me, it involves the creation of a 3D scene in a program like Blender. This can be textured and made to look like a photograph or made to look less realistic.
What they all have in common is that tey all involve artistic choices. and for me that is what makes digital art. It's a choice.
Read on if you want to learn more about my take on digital art, and if you want to see more digital art.