How does an e-cigarette work?

All e-cigarettes operate on a fairly simple principle: A liquid is converted to a vapour through the process of heating it. A battery sends an electric current to a wad of liquid-soaked wicking material that is tightly wrapped with a metal coil. Sending current to the coil causes the coil to heat up, much like a burner on an electric stove. Once the coil becomes hot enough, the liquid that is in contact with the coil also begins to heat up, eventually to the point the liquid becomes converted to a vapour. This vapour is then puffed or inhaled from the device. Because e-cigarette users are inhaling a vapour and not smoke, they often refer to themselves “vapers” to distinguish themselves from tobacco cigarette users. E-cigarettes come in all shapes and sizes and can be roughly categorized according to their simplicity, flexibility, and capacity. Another important distinction between devices is whether they are a closed or open system. Closed system devices cannot be modified by the user. The battery, coil, and chamber holding the fluid are self-contained. The only flexibility is being able to switch fluid cartridges to change flavour or nicotine strength. In contrast, all aspects of open system devices can potentially be changed to suit the user.