Alloism means breaking apart the pieces and treating them individually. Holism means one treats the whole.
In it, one does not treat the disease without treating the patient. One does not treat the patient without also treating all aspcts of thr patient, and taking all elements of ther patient into account in the presenting problem (the disease).
Said differently, the wholistic physician does not treat just the physical aspect of man. He or she takes into account and treats the patient on his or her every level: spiritualy, emotionally, mentally, socially, culturally, contextually--the whole of man and his setting.
In my opinion, this is medicine practiced at its absolute finest.
A quick read that is excellent is Anatomy of an Illness by Norman Cousins. He also wrote Head First.
Most have their own flavor to what holistic philosophy is. The above is my take on it.