What is a Mod? What's an APV? What's the difference? Once upon a time all e-cigs were little batteries shaped like sticks and designed to imitate the look and feel of a tobacco cigarette. As people tried them it became obvious that those little batteries could not provide enough power to be an effective substitute for smoking (for most smokers anyway), and so people started to modify the e-cigs to work better--or to modify other things (like flashlights) to use the atomizers but provide more power. At this point in time, anything that had a removable battery and/or wasn't pretending to be a cigarette was called a "Mod." It's been a few years and eGos/Rivas/Kgos/etc have become so commonplace that they are not even considered "mods" anymore but are in the same category as the cig-alikes. "Mods" have become so prevalent that most of them are now made in factories and purpose-built for vaping. And some people have decided that the term "Mod" is not relevant to mass-produced devices that are doing exactly what they are designed to do. In fact, enough people have decided this that there are several contenders for a "new name"--so now Electronic Cigarette / e-cig / eCig / PV (personal vaporizer) refers to any device that produces vapor (as opposed to smoke) for direct inhalation while Mod / APV (advanced personal vaporizer) refers to any PV that requires more knowledge/effort than simply opening the box and pushing the fire button. What is the difference between Mechanical and Electronic Mods/APVs? Mechanical Mods/APVs are built in such a way that the component of the device itself make all the connections and form all the electrical pathway--there are no wires or electronic components involved. Electronic Mods/APVs usually (but not always) have some sort of electronic board inside them that regulates the electrical current in some way. There will be wires and solder involved, and the efficiency of the device can depend greatly on the type of solder used and how well the joints are made, as well as the type and gauge of wire used. Many people consider mechanical devices "more reliable" than their electronic counterparts because there are no wires to break or components to fail, however they do usually involve more maintenance since they need to be disassembled and cleaned regularly (some more often than others) in order to ensure good electrical contact. On the other hand, many people consider electronic devices to be "more reliable" since the electrical pathway is "internal" and so does not depend on proper maintenance and cleaning nearly so much. What's the difference between Variable Voltage and Variable Wattage? The two most common types of electronic Mods/APVs are variable voltage and variable wattage. Both allow you to vary the amount of electricity passing through the coil of the *omizer and thus adjust the temperature at which your juice is vaporized, but they do so in different ways. Variable voltage devices adjust the voltage passed from the battery to the coil in order to increase or decrease the power (wattage). Variable wattage devices actually monitor the power being produced and adjust the voltage passed from the battery based on the resistance of the coil. How this basically works out is: Variable Voltage lets you control the voltage of the battery, changing the power used by the coil based on its resistance. As the coil ages its resistance will change and you may need to adjust the voltage to compensate. Also, different coils have different resistance (even if they are in the same package with a specific resistance on it) and so the voltage may need to be adjusted up or down every time you switch to a new *omizer. Variable Wattage lets you choose the final power setting at which you vape and the device automatically adjusts the voltage based on the actual resistance of of the coil. This means that whether the coil changes value, or you switch to a compleatly different coil (even one with a wildly different resistance), the device will automatically adjust the voltage to compensate. So which is best? That is entirely dependent on what you want to do with it and your personal tastes and preferences. Mechanical Mods are climbing in popularity as more and more people move to rebuilding their own coils for RBA's and/or replaceable heads. They are more forgiving in the sense that your coil does not have to be 1 to 1.2 ohms or higher for your device to operate as Electronic PV's usually see resistance that low as a short circuit and refuse to operate. On the other hand, the Electronic APV's with variable controls are also rising in popularity as people discover the joys of exploring how flavours change with slight (or not-so-slight) adjustments to the power (temperature) at which their juice is vaped.