This document discusses infusion pumps, which are external medical devices that deliver fluids like nutrients and medications into a patient's body in controlled amounts. It describes different types of infusion pumps based on their size, portability, and mechanism of delivery. The key types discussed are gravity infusion devices, volumetric pumps, patient-controlled analgesia pumps, and syringe pumps. The document also outlines important safety considerations, components, and functions of infusion pumps.