Holistic means encompassing the whole of a thing, and not just the part. Holistic medicine looks at the whole person for answers, not just at physical symptoms.
You might have heard of holistic medicine, which tries to treat someone as mind and body, instead of treating only the part of the patient that is most sick. People often talk about holism in relation to healing, whether of bodies or other things. A holistic approach to solving a labor dispute would take into consideration the needs of both the workers and the factory owners.