
"Cigalike" e-cigarettes look like a traditional tobacco cigarette, with a light at the end that glows when the user draws on it. The battery-powered device heats "e-liquid," containing nicotine, which is released in aerosol form.

"Tank" e-cigarettes are heavily stylized and modifiable. They contain a larger cartridge of e-liquid and a battery pack that can be recharged, some by USB.

"Electronic nicotine delivery systems" now take a variety of forms. E-hookahs have also been developed and have a strong cross-cultural market potential.

A delegate at the "E-Cigarette Summit" smokes an e-cigar. In the e-liquid, nicotine is usually suspended in propylene glycol and glycerine.

E-pipes work on the same principle. When someone draws on the device, it detects the air flow and heats the e-liquid in the cartridge to form a vapor.

Vaporizers have also been adapted for marijuana. They have been developed for the medical market and contain cannabidiol (CBD), a method of pain-relief for glaucoma and migraines, while omitting THC, which causes the "high."

Nicotine gum and patches predate ENDS as a way for people to attempt to give up cigarettes.