The Earth has vast reserves of ocean water. Around 97 percent of total water is found in the oceans and, simultaneously, 70 percent of the earth’s area is covered with oceans. The world’s generally all sea; mountains; lakes; and the snow and water emerging from the mountains; all get accumulated and meet in the oceans. The oceans found on Earth are monisms in our solar system. No such oceans are found on any other planet. Oceans have a whole world filled with mysteries and diffusion. Every living thing in the ocean is there to create amusement for us. Despite so much research, several mysteries of the oceans remain unsolved. The oceans, rivers, lakes, and trees are very important to us and our environment as they provide us with fresh and clean water and food. Rivers flow from several origins. These origins can be lakes and mountains. Almost every river meets another river or ocean at the end of its journey. The river which meets the main river is called the tributary. The area through which a river passes is called its catchment area. To maintain the level of the river and its flowing speed, it is necessary to make sure that we don’t exploit the catchment area. Many rivers become the cause of floods in many places in the monsoon season. If the river is large, then it can affect a large area. The rivers that carry a lot of topsoil with them often form deltas. Many forests grow on the banks of the rivers, including several species. Many fish have adapted to living in the rivers as well as the seas, like the Hilsa and salmon fish. For thousands of years, rivers have played an important role in the lives of human beings, and this is the reason why many important towns and cities are located on the banks of rivers. We love our rivers; we pray to them, but we also pollute them. We use the river for drinking, and bathing, as a means of transportation and entertainment. We also use it to generate electricity, and then we throw the waste into the rivers. This is not taking advantage, but in this way, we are ruining our future. We started using rivers as a means of transportation 3,300 years ago. This happened when people floated a boat for the first time on the river Indus. From that time till now, we can see several rivers used as a means of transportation. Some of these rivers are the Ganges, Nile, and Mississippi Missouri. We catch a lot of fish from these rivers, which also help us with irrigation. It is often said that our world resides in a small seed. In the same way, a small seed has a whole tree inside it. These trees and plants are our first mothers. Their leaves, flowers, roots, fruits, and seeds are a part of our daily diet and provide us with nutrition. Without these trees, our world is incomplete. They provide us not only with food but also with oxygen. They absorb carbon dioxide and release oxygen. They also provide shade for the animals and a home for the birds. Some plants are also used for medicine, mostly herbs. Neem is a good example of medicine. The roots, leaves, seeds, and bark of the Neem tree are all used to make medicines. Plants and trees control the atmospheric temperature. You must have noticed that the places with a lot of trees are mostly pollution-free and have a cool temperature. We all know that without trees, life is impossible. If no trees are left, then our beautiful planet will become dry and lifeless. We should understand the need to plant trees. Our ancestors gave us a green environment, and we should give the same to our future generations. In this book, detailed information has been given about our oceans, rivers, and lakes, and a brief description of life-giving trees has been given. After reading this book and understanding the role these natural resources play in our lives, we may understand their importance. In Mahatma Buddha’s words, "The trees are magical beings in this world. They provide shade to all, even to those who come with axes to cut them down.”