san�i�ta�tion (săn'ĭ-tā'shən)
Formulation and application of measures designed to protect public health.
Disposal of sewage.
hy�giene (hī'jēn') The science that deals with the promotion and preservation of health. Also called hygienics.
Conditions and practices that serve to promote or preserve health: hygiene in the workplace; personal hygiene.
In other words, hygiene is the objective, while sanitation is one of the tools for achieving it.
I can't really see what the difference in meaning is between 'application of measures' on the one hand and 'practices' on the other, as outlined in Ewood's answer. In other words, the two definitions seem to be saying very much the same thing. Certainly Chambers 'Thesaurus' lists them as synonyms, so I think you can take it, Keitra, that - for day-to-day circumstances - there really is no difference. (No offence meant, of course, E.)