A phial is a small container, often made of glass or plastic, used to hold liquids or powders. It is commonly used in laboratories, pharmacies, and for storing samples. Phials can come in various sizes and shapes, and they often have a secure closure to prevent leaks or contamination. In the context of medicine, phials are frequently used to store medications, vaccines, or other biological substances. They are designed to protect the contents from light and air, ensuring the stability and effectiveness of the stored material. Phials are essential tools in fields like pharmacy and laboratory research.