The general purpose category hopefully comes off as self-descriptive. The hooks in this category can be used for a variety of things such as bait fishing, tied into a fly or lure, rigging soft plastics, etc. Granted, each hook design has its strengths and weaknesses but in a pinch, you could swap out any of these hooks and still catch fish. Anglers should feel empowered to experiment with all these hook styles to find a hook that suits them best.
The specialty category indicates these hooks are designed and sold for a particular purpose. It does not mean you can't repurpose them, but you should give pause before purchasing with a different use case in mind. Given how particular these hooks can be, they might not work at all when fished as not intended.