Dear student
Hydrolysis - It is the process of using water to break the molecule into two parts. Hydrolysis means "Dissociation" of water into two groups like H+ and OH-.
Dissociation - It is the reaction where any molecule breaks into its constituent ions or components. Dissociation means breaking group into two opposite charges so as to add or react.
One major difference is that hydrolysis is limited to dissociation of water, But dissociation is not limited.
Regards