The "Hypodermic Needle" is a medical instrument used to inject substances into the body or extract fluids. It consists of a hollow needle attached to a syringe, allowing for precise delivery of medications, vaccines, or other solutions directly into the bloodstream or tissues. This method is commonly used in hospitals and clinics for various treatments. The design of the hypodermic needle has evolved over time, improving safety and effectiveness. It is often used in conjunction with vaccines to prevent diseases, and its use is critical in emergency medicine for administering life-saving drugs quickly.