Answer is: The ions in the solute separate from each other.
For example, dissociation of potassium iodide in water:
KI(aq) → K⁺(aq) + I⁻(aq).
Solvation is the interaction of solvent (water) with molecules or ions (in this example K⁺ and I⁻) in a solute.
Anion I⁻ has negative charge, so positive end (hydrogen atoms) of a water molecul attracts them.