I'm often amazed just how few people understand what digital art really is. It's not the first time that someone has wanted to buy the original of a digital print so I thought I would give some explanation here. As the saying goes, there's many ways to skin a cat, and so is the case with digital art. I personally use two methods: either painting over a photo or combination of photos, or as an original piece on a blank screen. For the photo method, I tend to use photoshop but for the other I use usually the Artrage software on my Mac which is the version that I'll show here.
The hardware that I use is a desktop Mac which has a separate touchscreen ( Wacom Cintiq 13HD) attached by a cord. The touchscreen is similar to a tablet like an iPad except that it has no software or memory, that's all on the Mac. The screen doesn't respond by my fingers either, but only to a very sensitive stylus (rather like an Apple Pen which came out later). The stylus is touch sensitive and detects the pressure and angle that I use it.
The software is Artrage but I sometimes use Sketchbook Pro. The programme starts with a blank screen which I adjust for the finished size and format and I can select any medium from pencil through watercolour to oil paint. I can also select any type of brush, knife, spray, pastel, etc. It has every given type of medium and replicates it brilliantly on the screen.
My own preference just now is pen and ink. It gives a nice strong colour and lines that suits the type of prints that I'm producing just now. I usually start of with a very loose sketch such as below to get an idea of composition and colour.
I then just start on the finished work, usually starting on the background and moving into the foreground.
This is all done by hand using the stylus, no photographs are used except as perhaps a source to use on the Mac monitor (i.e. I needed a photo of the dog to copy from). The big advantage to digital art is that I can place different parts on what are called 'layers'. For instance, the dog is on a separate layer which means that I can move him anywhere on the picture without disturbing the other elements, or even scale him to a different size or replace him with a charging elephant if the mood takes me. Eventually, if I'm happy, I have the finished piece but being digital, I can adjust bits if I feel they're not working. I can also adjust saturation or tones or anything that bothers me.
Once completed, the original stays on the computer like a digital photograph but can be printed at any size and in any quantity. That's as best as I can describe digital art.