Syringes are medical devices used to inject or withdraw fluids from the body. They consist of a barrel, plunger, and needle (or nozzle), with variations in size and design depending on their intended use. Syringes are commonly used in healthcare for administering medications, vaccines, or fluids intravenously, subcutaneously, or intramuscularly. They play a critical role in medical treatments, diagnostic procedures, and managing various health conditions.