Tree species refer to the different types of trees that exist in nature, each with unique characteristics such as size, shape, and leaf structure. Common examples include oak, pine, and maple. These species can be classified into two main categories: deciduous trees, which lose their leaves in the fall, and coniferous trees, which usually remain green year-round. The diversity of tree species plays a crucial role in ecosystems, providing habitats for wildlife and contributing to air quality. Trees also offer resources like timber and fruit, making them valuable for both environmental and economic reasons. Understanding tree species helps in conservation efforts and sustainable forestry practices.