"Intravenous" refers to a method of delivering fluids, medications, or nutrients directly into a person's bloodstream through a vein. This technique is commonly used in hospitals and clinics to provide quick and effective treatment, as it allows for immediate absorption and action of the substances administered. The process typically involves inserting a thin tube, called a catheter, into a vein, often in the arm or hand. This method is essential for patients who cannot take medications orally or require rapid hydration, such as those undergoing surgery or experiencing severe illness.