A circular economy is a model of production and consumption that aims to keep materials, products, and services in circulation for as long as possible, reducing waste and pollution. It involves sharing, leasing, reusing, repairing, refurbishing, and recycling existing materials and products. The circular economy is based on three principles, driven by design: eliminate waste and pollution, keep products and materials in use, and regenerate natural systems. The circular economy is a framework that targets zero waste and pollution throughout materials lifecycles, from environmental extraction to industrial transformation, and final consumers, applying to all involved ecosystems. The circular economy is underpinned by a transition to renewable energy and materials, and it is accelerated by digital innovation. The circular economy tackles climate change and other global challenges, like biodiversity loss, waste, and pollution, by decoupling economic activity from the consumption of finite resources. The circular economy provides a framework that allows governments and cities to realize many of the Sustainable Development Goals (Global Development Goals) and an extension of a green economy. The circular economy is an economic concept often linked to sustainable development, provision of the Sustainable Development Goals (Global Development Goals) and an extension of a green economy.