CITES protects over 5,800 species of animals and 30,000 species of plants to prevent over-exploitation through international trade. Over-exploitation refers to harvesting resources at rates higher than populations can withstand, which can lead to resource destruction or extinction. Species are listed in CITES appendices according to threat level, with Appendix I being the most threatened and Appendix III the least. The document provides examples of species in each appendix category for mammals, birds, reptiles, amphibians, fish, invertebrates, and plants.