Vape pens are portable devices used to inhale vaporized substances, commonly nicotine, cannabis, or flavored liquids. They consist of a battery, a heating element, and a cartridge or tank that holds the liquid. When the user activates the pen, the heating element warms the liquid, turning it into vapor that can be inhaled. These devices are popular alternatives to traditional smoking methods due to their convenience and variety of flavors. Vape pens come in different sizes and styles, making them easy to carry and use discreetly. They are often marketed as a less harmful option compared to conventional cigarettes.