This document provides information on electronic cigarettes (e-cigarettes). It describes how e-cigarettes work by heating liquid nicotine into an aerosol, and that they are available in various flavors and refillable or disposable models. The document summarizes research showing e-cigarettes may be a gateway to traditional cigarettes for youth and that their vapor contains toxic chemicals. It also outlines marketing tactics used to promote e-cigarettes that mirror traditional tobacco and concerns they could re-normalize smoking.