There are a variety of models available in the market, but the three basic types are: e-cigarettes cigalikes, eGos and mods.

Rechargeable Cigalikes

The rechargeable cigalike is the combination of two words “cigarette” and “alike” and were designed initially to look and feel like traditional cigarettes. They look similar to cigarettes made from tobacco.
Most people who continue to vaping after switching from cigarettes also leave disposable e-cigs and use a rechargeable cigalike electronic cigarette unit, consisting of a rechargeable battery and a clearomizer or cartomizer.
The two-piece Cigalike comes with an atomiser-containing cartridge and a rechargeable battery (and USB charging cable). The cigalikes are very small and light.

Mods

Modified systems or modes have a larger tank, bigger battery and more customisation options. Long-term vapors often use a palm battery vapor with a Vapor Mod, and while outside the building, they still have e-cigs or vapor pen.
Mods go by a lot of names like mechanical mods or sophisticated personal vaporisers. Every vaporiser that is not a cig or a vapor pen may be referred to as a mod.
Mods are available in various shapes and sizes but are usually the largest electric cigarettes. They have a rechargeable tank, longer batteries and variable capacity.

eGo E-cigarette

The eGo is probably the best-known electronic cigarette model in the industry. It is significantly larger and performs better than a cigalike. It is economical, offers longer battery life, has an attractive appearance and promotes low-resistance atomisers to provide a smaller e-cigarette with some of the best vapor production possible.
Although it’s quite small,  many e-smokers like them