Airflow Sensor
Modern electronic cigarettes contain an electronic airflow sensor – its purpose is to activate the atomizer when it detects that the user is inhaling. Early generation devices had a manual switch rarely found these days.

Atomizer
Sometimes referred to as a heating element, the atomizer heats up the solution in the cartidge, turning it into vapor. On some models, the atomizer and cartridge are combined into one unit called a Cartomizer.

Battery
Electronic cigarette ‘batteries’ contain microelectronics in addition to a rechargeable lithium-ion battery. The electronics are responsible for, amongst other things, switching the atomizer on and off and activating the LED at the tip.

Cartomizer
An atomizer and cartridge in one unit

Cartridge
This part of the device contains the nicotine solution, situated where the filter would be on a normal cigarette. It’s composed of propylene glycol (or sometimes glycerin), nicotine in varying concentrations and flavoring.

LED (Light Emitting Diode)
Many models of electronic cigarette contain a small light on the tip which is switched on when the user inhales, making the device look more like a traditional cigarette.

Propylene glycol
One of the components of the liquid in the cartridge, propylene glycol is heated to create the vapor inhaled by the electronic cigarette user. It is widely used in cosmetics, foodstuffs, toothpaste, mouthwash and artificial smoke generators for theatrical productions.