Medicines are substances used to prevent, diagnose, treat, or alleviate symptoms of diseases and health conditions. They can come in various forms, including tablets, capsules, liquids, and injections. Medicines work by interacting with the body's systems to restore health or improve well-being. There are two main types of medicines: prescription and over-the-counter (OTC) medications. Prescription medicines require a doctor's approval and are tailored to specific health needs, while OTC medicines can be purchased without a prescription for common ailments like headaches or colds. Both types play essential roles in healthcare.