Vaporizer pens can be used to inhale a number of different materials. Often, people call vaporizer pens by names that indicate what they are used to vape. The three main types include: - The oil vaporizer pen, which is also called an oil pen or oil vape pen.
The United States is the world's largest economy with a GDP of approximately $18.56 trillion, notably due to high average incomes, a large population, capital investment, moderate unemployment, high consumer spending, a relatively young population, and technological innovation.
China had the largest economy in the world for much of the last 500 years, during which it has seen cycles of prosperity and decline. Since the introduction of economic reforms in 1978, China has become one of the world's fastest-growing major economies. As of 2014, it is the world's second-largest economy by nominal GDP and largest by purchasing power parity (PPP).