E-liquid, also known as vape juice, is a liquid used in electronic cigarettes and vaping devices. It typically contains a mixture of propylene glycol, vegetable glycerin, flavorings, and nicotine, although nicotine-free options are also available. The liquid is heated in the device to create an aerosol, which users inhale. The flavorings in e-liquid can range from traditional tobacco and menthol to a wide variety of fruit, candy, and dessert flavors. E-liquids come in different nicotine strengths, allowing users to choose their preferred level. This versatility has contributed to the popularity of vaping as an alternative to traditional smoking.