The text is mainly about the importance of the ocean and its impact on human well-being, livelihood, and global biodiversity. It also discusses the diversity of deep-sea marine habitats and organisms, the role of the ocean in shaping global climate change and ecosystems, and the abundance and variety of marine life. The chapter emphasizes the need for understanding the structure and function of ocean ecosystems and the necessity for balanced and resilient ecosystems for greater adaptability to change.