An electronic cigarette (a.k.a. e-cigarette, e-cig, or personal vaporizer) is a battery-powered device that provides inhaled doses of nicotine by way of a vaporized solution. Electronic cigarettes come in many shapes and sizes.
Some are long, some are short, some are thin, some are thick…and some are square. E-cigs were first released in 2006, and have improved during the past 5 years. In the beginning, atomizers were rare to last longer than a few weeks.
Now, however, most come with 3 or 6 month warranties. It is usually the same for batteries. Electronic cigarettes are mainly used by those who want to stop smoking traditional cigarettes, for a variety of reasons ranging from price of cigarettes to health concerns to more personal reasons.
More information you can find here http://esmokinginstitute.com/en/