An electronic cigarette (or e-cigarette), personal vaporizer (PV), or electronic nicotine delivery system (ENDS) is an electronic inhaler meant to simulate and substitute for tobacco smoking. It generally utilizes a heating element that vaporizes a liquid solution. Some release nicotine, while some merely release flavored vapor. They are often designed to mimic traditional smoking implements, such as cigarettes or cigars, in their use and/or appearance.