E-cigarettes or PV's:
PV stands for Personal Vaporizer. A PV (also known as an e-cigarette) is a device that warms atomized liquid into a vapor which can be inhaled by the consumer. These vapors often contain nicotine and flavorings, and are used to simulate a smoking experience, without the actual smoke.
Atomizers are a small device component, metal casing surrounds a small ceramic pot that holds your e-liquid. There is a NiChrome coil inside of the ceramic pot which is heated to vaporize e-liquid into nicotine mist. Atomizers are the work-horse of the E-cigarette, when the battery of an e-cig is activated, a charge is sent to the atomizer from the battery or power source, warming the NiChrome coil inside of the atomizer. The atomizer then heats the liquid into a vapor ready for inhalation. Atomizers work by vaporizing liquids and do not cause combustion, so the atomized vapor carries nicotine and simulates smoke without actually creating it.
Batteries are often the largest or longest part of the e-cig, forming the body of the device. A battery's primary function is to power the atomizer, and control the on/off function of the device. Most electronic cigarettes will have a glowing LED on the end to either simulate a cigarette "cherry" which is to notify you when the battery is active and sending a charge to the atomizer. The LEDs are also available in colors like blue and green so as to not be mistaken for real cigarettes.
The battery reacts to an internal switch that is either activated automatically or manually. An automatic battery does not have a button on the device, and is activated by either microphone or pressure sensor in the device. Automatic batteries can be activated by sensing someone taking a puff or 'draw' on the device. Manual batteries are activated by the press of a button, allowing more control over when the battery is active or not.
Cartridges and Drip Tips:
Cartridges or "carts" are simple plastic reservoirs that hold liquid inside. Most cartridges make use of a poly-fill stuffing that holds in liquid but still allows it to be "wicked" down into the atomizer by the atomizer bridge. Cartridges are also available without liquid for those who prefer to fill their own. Some cartridges are considered "tank systems," which have no poly-fill stuffing, and slowly leak liquid into the atomizer.
Drip tips are replacements for cartridges, which allow the user to drip nicotine liquid directly into the atomizer, giving fuller control of the atomizer's function. Drip tips should be used by advanced e-cigarette users (vapers) as overfilling, or under filling the atomizer can damage your unit.
Cartomizers are one-piece atomizers with attached cartridges. The metal tube of the cartomizer is filled with a poly-fill stuffing similar to the cartridge, which holds the e-liquid. In the center of the stuffing is a wire with a nichrome coil similar to the atomizer. In this unit the liquid is kept in the same part of the e-cig as the heating coil. The advantage of cartomizers is that they hold more liquid, however they are considered disposable pieces.
A passthrough is a replacement for the battery device that connects to an atomizer, but instead of a battery it plugs directly into a power source via USB or wall socket. Passthroughs are a good way to save time and not change batteries. Also great in the car (with USB-Car adaptor) or at the desk! Although they usually will not function without a steady source of power, they can provide larger voltage capabilities than e-cigarette batteries, and do not require charging. Some passthroughs are passthrough/battery combinations - or USB batteries.
Mods are a short term for electronic cigarette 'Modifications.' Usually non-traditional in design, mods provide a variety of new functions to the e-cigarette in terms of durability, battery life, or increased voltage. E-cigarettes come in a variety of designs, shapes, sizes, and functions. Each is different in it's own right.