Electronic cigarette is also termed as e-cig, personal vapor, Electronic Nicotine Delivery System (ENDS). Smoking a e-cigarette is now termed as vaping, as now modern e-cigarette produce vapour form the liquid in its tank. There are many types of e-cigarette and wikipedia has even categorised them as by generations from first to third.
First generation e-cigarettes are termed as ‘cigalikes’ as they look like a normal cigarette in shape, they have a LED light that signals user it is working/activated as they inhale from mouth piece. These e-cigarette consist of battery component and e-liquid (e-juice) Component. Few models have rechargeable batteries.
Second generation are termed as Personal vapor (PV), these are much famous and used widely. PV consist of two parts one is the battery part and another is the e-liquid tank (Clearomizer), they can be refilled without changing the tank. Batteries are rechargeable with USB charger, and are available in various power capacity like 950 mAH, 900 mAH, 1100 mAH and so on. Maximum of all batteries have a switch to power On and Off, same button is used to heat up the coil inside atomizer which is placed with the silica fiber soaked with e-juice which make the vapour.
Third generation are termed as Mechanical Mods, these are the huge sized PVs which have higher battery power and are shaped like a box or a cylinder. These mods have a battery installed which can be replaced by user after it is dead(depleted) and cannot be used any more. Atomizer are rebuildable and can be customized to get huge vapor from each hit. Clearomizers are also huge to hold more e-liquid.
E-Cigarette can be bought online or from a local store, E-Cigarette price starts from $5, price is higher as the generation of e-cigarette climbs up.
Now electronic cigarettes are more like hobby rather than quitting traditional (fire) tobacco cigarette.