Hydration vs Dissolution While revising Thermodynamics and Thermochemistry from revision material published by Arihant publications I encountered the following mentioned statement.

During dissolution, the physical state of the compound changes while during hydration, there is no change in the physical state of the compound.


How does dissolution result in a change in physical state?

Should not hydration (or solvation in general) be the same as dissolution as in both the bonds of solid salt to be dissolved or solvated weaken and a new bond is formed between constituents of salt and the solvent? Could someone please explain what I'm missing?
Before dissolution, the substance is usually a solid and forms crystals. Its physical state is solid. After dissolution, the substance is not visible any more : it is not a solid any more. Its physical state has changed.
Before hydration, the substance is usually solid. After hydration, the color and the volume may have changed, but the physical state has not changed : it is still a solid –