Rainwater tanks are becoming increasingly popular as a way to store and conserve water for domestic and commercial use. Some common synonyms for rainwater tank include water storage tank, water cistern, rain barrel, water reservoir and water harvesting system. Water storage tanks are used to store rainwater and can be made of various materials such as plastic, concrete or steel. They come in different sizes, shapes and types, including above ground and underground tanks. Water cisterns are similar to water storage tanks, but are typically used for larger-scale water storage. Rain barrels are smaller, portable containers that can be placed under gutters to collect rainwater for gardening or other outdoor uses. Water harvesting systems are more comprehensive and involve various components such as gutter systems, filtration systems and pumps to capture, filter and distribute rainwater for use in homes or businesses.