Corporate sustainability means that a big business is doing things to help the environment and make sure it stays healthy and strong. They do this by using energy and resources in a responsible and sustainable way - which means they don't use too much so that it doesn't get wasted. A business might also try to use materials and products that come from sustainable sources and don't harm the environment. For example, a business could use solar panels instead of electricity from a power plant or use recycled materials in their products. This helps the environment, and makes sure the company is being responsible.