E-cigarette, short for electronic cigarette, is a reusable electronic nicotine delivery device. This can be used in buildings, don't apply to "no smoking" laws, have three to four ingredients, saver then cigarettes, no ash, no butts and extremely lower cost than traditional cigarettes. Most resemble a real cigarette, while some look like writing pens. They consist of three main parts: a battery, an atomizer and a cartridge..