The primary distinction between terrestrial and marine ecosystems lies in their environmental characteristics and species adaptations. Terrestrial ecosystems are defined by land-based environments, featuring a variety of climates, soil types, and plant communities, which support diverse animal species. In contrast, marine ecosystems encompass oceans, seas, and estuaries, characterized by varying salinity levels, water depth, and light availability. The organisms in these ecosystems have adapted to their specific conditions, with aquatic species exhibiting features such as gills for respiration and buoyancy adaptations. This fundamental difference influences the biodiversity, productivity, and ecological interactions within each system.