Krita is a free and open-source digital painting application. It's designed for concept artists, illustrators, VFX artists, and texture artists, and others. Krita offers a wide variety of brush engines, blending modes, filters, and other tools to create stunning digital art. It supports layers, masks, and transforms, and it can be used to create animations and comics. To start, download and install Krita, then explore the interface and experiment with the different tools and brushes.