Aeration is the process of introducing air into a substance, commonly used in soil management and water treatment. In gardening, aeration helps improve soil structure, allowing roots to access nutrients and water more effectively. It can be achieved through methods like using a garden fork or specialized machines that create small holes in the ground. In water treatment, aeration involves adding air to water to remove impurities and enhance oxygen levels. This process is essential for maintaining healthy aquatic environments and is often used in wastewater treatment plants to promote the growth of beneficial bacteria that break down pollutants.