Also, it's not uncommon for an artist to work in more than one of them I use both Corel Painter and Photoshop CS6 along with other Inkscape for vector art and learning Blender for digital 3D. Other good options for digital art software are Procreate, Clip Studio Paint, Art Rage, and Krita, but there are loads more. If doing it primarily for you own enjoyment than it doesn't matter so much which program and there are many options out there, some even for free.

Corel Painter is another excellent professional level painting program and a close rival to Photoshop. If professionally, while there are other very good professional software out there, Photoshop is still the industry standard across the board on 2D digital art, whether matte painting, digital painting, photobashing/photomanipulation, etc. Are you planning on doing digital art professionally or just for a bit of fun? Also, what type of digital art? Photomanipulation, digital painting, both? Some programs are better at one type of digital art than another. It all depends on what your needs are as an artist.

Medipang paint