Oxygen is a life-giving necessity for nearly all forms of life on Earth. It is used to create the energy that powers cells, to help cleanse the air, and its abundance in the atmosphere makes it an essential part of the protective ozone layer. In short, oxygen plays a vital role in many aspects of life on our planet. Oxygen is one of the most abundant elements on Earth, making up about 21 percent of the Earth's atmosphere by volume. Nearly every living organism needs oxygen to survive. In humans, oxygen is used during breathing, as well as to produce energy in cells. It also helps to regulate metabolism and other important biological processes. Oxygen plays an essential part in photosynthesis, helping to capture energy from the sun and convert it into food molecules, allowing plants to grow and provide oxygen for other living organisms. In addition to its role in life on Earth, oxygen has many important industrial applications. It is used to produce steel, certain medical treatments, and even fuel in the form of liquid oxygen. Its ability to oxidize other materials makes it a useful tool in manufacturing processes. Oxygen can also be a hazard, as it can promote the growth of harmful pollutants such as smog, and become explosive when concentrated in large amounts. Overall, oxygen is an incredibly important element in many aspects of life on Earth. From serving as a necessary part of the atmosphere, to aiding in the growth of plants and the production of energy, oxygen's role in life on our planet cannot be overstated.