Intravenous administration is a medical technique used to deliver fluids, medications, or nutrients directly into a patient's bloodstream through a vein. This method allows for rapid absorption and immediate effects, making it essential in emergencies or for patients who cannot take medications orally. The process typically involves inserting a thin tube, called a catheter, into a vein, often in the arm or hand. Once in place, healthcare professionals can administer various treatments, including antibiotics, chemotherapy, or hydration solutions, ensuring precise control over dosage and timing.