This document provides an overview of environmental science concepts including the definition of environment, components of the environment, ecosystems, biodiversity, and conservation efforts. It defines environment as the sum of all biotic and abiotic factors surrounding an organism and influencing its life. Key components include the lithosphere, hydrosphere, atmosphere, and biosphere. Ecosystems are formed by the interaction of biotic and abiotic factors in an environment. Biodiversity refers to genetic, species, and ecosystem diversity and is threatened by human activity like habitat loss. Conservation efforts include both in situ and ex situ methods to protect biodiversity.