As a tiny part of nature, it's our moral and social duty to understand and protect our environment. The environment gives us all and everything, either direct or indirect, ways to sustain our life. On the other hand, we humans destroyed our environment and crucially hampered our natural system. This book includes its components, effective way of its uses, importance in our daily life, and how to conserve it. In this book, we simplified the concept of Ecology, Environment, Biogeochemical cycle, Environmental Pollution and its regulation, Biodiversity and Conservation, Biome, Natural Resources and its Sustainable Development, Symbiotic Associations, Bioindication, Waste management and environmental issues etc. Moreover, we illustrated some exciting figures of mentioned topic and subtopic to understand the readers better. Now a day it's imperative to know about our nature, how to use its resource and its sustainability, way of conservation and to protect biodiversity, animal-plant interaction and so on. For further clarification of readers, we put some FAQ, valuable references, web help and essential books at the end.