Biodiversity is an important component of nature’s valuable assets that meet many human requirements and protect against environmental disasters. Over the last decade, biodiversity has become an increasingly appealing topic for researchers due to the extinction of plant and animal species, climate change, air pollution, advances in technology and industry, development of agricultural and urban lands, and changing human attitudes towards species, ecosystems, and landscapes. The presence of life on Earth is the most distinguishing feature, and the diversity of life is the most astonishing feature. The Earth is home to over nine million different protists, fungi, plants, and animal species. The loss of biodiversity affects the functioning of the biodiversity and also affects Earth’s life. Conservation of biodiversity is the top priority to protect the life of the endangered species and to sustain their niches. This chapter highlights the biodiversity, its importance, and its classification.