The science of ecology studies interactions between individual organisms and their environments, including interactions with both conspecifics and members of other species. Though ecology emerged in the 19th century much of its theoretical structure only emerged in the twentieth century. Though ecology includes a wide variety of sub-fields, philosophical analysis of ecology has so far been restricted to population, community, and ecosystem ecology. Central philosophical problems include explication of relevant notions of ecological diversity and stability the relation between diversity and stabilityIn this book we simplified the concept of Ecology, environment, pollution and its regulation, biodiversity and conservation, ecotourism etc. We illustrated some respective figures of mentioned topic and subtopic for better understanding of readers. Now a day it's very important 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.