Hi,
in summary, Vestibular Rehabilitation treats the symptoms of dizziness and decreased balance.

It is characterised by a formalised assessment process, including presentation/ history, symptom description and a thorough physical assessment of the oculomotor, vestibular and balance systems.
Analysis/ evaluation of the above will guide the treatment. Options include oculomotor training, vestibular adaptation and/ or substitution exercises, certain manouvres, habituation exercises and balance training - whatever the assessment findings lead you to.
Or sometimes, you might conclude that the problem lies in an area, which Physio is unable to treat, in which case you will refer on to Medical Specialists, e.g. Neurologist, ENT, ...

The focus is on decreasing or diminishing the occuring problems - whatever they are.

Hope this helps for a start,
regards,
Fyzzio