Oxygen compounds are chemical substances that contain the element oxygen combined with other elements. They play a crucial role in various chemical reactions and are essential for life. Common examples include water (H₂O), which is vital for all living organisms, and carbon dioxide (CO₂), produced during respiration and used by plants in photosynthesis. These compounds can be classified into different categories, such as oxides, peroxides, and hydroxides. Oxides are formed when oxygen reacts with metals or nonmetals, while peroxides contain a higher ratio of oxygen. Understanding oxygen compounds is important in fields like chemistry, biology, and environmental science.