Ginger is a root, the rhizome of Zingiber Officinale, and grows in fertile, moist soil (definitely not where I come from). Unlike most spices when ginger is used fresh, not dried, it is still called a spice. Typically the root is dried, and ground to a powder, or the oils from the ginger are extracted and used medicinally.
Ginger purportedly has many medicinal uses. Most of them are unproven by Western Medical Science, but well known in the Schools of Ayurveda, and in Traditional Chinese Medicine. I am not a trained Nutritionist, or part of the Medical Profession, yet I do believe in the power of herbs and spices to heal. And ginger is one of those spices. It is known as an anti-inflammatory, helping with Arthritis, nausea and vomiting in both pregnancy and chemo therapy patients. It is used to combat ulcerative colitis, heartburn and stomach upset. It is also used to treat Upper Respiratory infections. It may possibly help in heart-related disease, by lowering cholesterol. And there have been studies done to show its usefulness in alleviating motion-sickness. Ginger may possibly have cancer-fighting agents as well, but that remains unproven as of right now.