Holistic refers to the whole, rather than a part. Let’s use a health example, to understand it easier.
Conventional medicine looks only at the symptom: a tumor, an infection, an organ causing trouble. In general, they either do not know or do not care going to the origins – or they simply have no time to do so.
The holistic vision looks for the root of a problem and envisions the patient as a whole. Why did this disease start, in the first place? How do you feel, at all levels? What do you think? What do you eat? What level of stress do you have? What exercise do you do? What is your work situation, and that with your friends, your partner? What kind of inner (spiritual) life do you have? Have you been exposed to external factors (chemical products, radiation) that might have caused this situation?
Once this has been evaluated, you can look at which approaches you can use in the healing process. From herbs and essential oils to Reiki, Bach Flower essences, osteopathy/chiropractics or other touch techniques, massage, changes in eating and lifestyle, etc.etc. Sometimes the surgeon’s knife is necessary indeed, or the doctor is welcome to put the broken bone in its place and set a cast around, but this alone will never fix the root issue.