Pharmaceuticals are substances used to diagnose, treat, or prevent diseases and medical conditions. They can be classified into various categories, including prescription medications that require a doctor's approval and over-the-counter drugs that can be purchased without a prescription. These products play a crucial role in modern medicine, improving the quality of life for millions of people worldwide. The development of pharmaceuticals involves extensive research and testing to ensure safety and efficacy. Companies like Pfizer and Johnson & Johnson invest heavily in this process, leading to innovative treatments for conditions ranging from minor ailments to serious diseases. The pharmaceutical industry is vital for public health and medical advancements.