E-cigarettes, also known as electronic cigarettes or vapes, are battery-operated devices that heat a liquid solution containing nicotine, flavorings, and other chemicals to create an aerosol that is inhaled. Research on e-cigarettes primarily focuses on their potential health effects, efficacy as smoking cessation tools, patterns of use among youth and adults, marketing tactics, and regulation policies. Studies have shown conflicting evidence regarding the safety and efficacy of e-cigarettes compared to traditional tobacco products, with some suggesting they may be a less harmful alternative for smokers trying to quit, while others warn of potential risks associated with nicotine addiction and exposure to toxins in the aerosol. Ongoing research aims to better understand the long-term health implications of e-cigarette use and inform public health policies to regulate their marketing, accessibility, and use.