Once upon a time, a mod to most was a vision spinner 1 or an ego twist. You could modify the voltage and change the tank/clearo you used - well the vaping world has moved on a little since 18 months ago, and now a mod has a whole new meaning. Most of the new mods hitting the market offer variable wattage, which while it translates to a more customised performance for the user, most vapers don't really understand what variable wattage actually means for their experience.
Watts is the conversion of force to energy. For example a 4.5v battery is set to produce 10watts of energy and then at 20watts. The higher the amount of watts, the more work that is being done in that same given time. Therefore, in vaping terms, a higher wattage produces more cloud as the juice is being vaporised at a faster rate. This is the simplest explanation and does not take into account ohms or resistance of a tank or clearomiser.
Resistance is exactly what it sounds like, its the resistance/protection between the juice and the power source, in this case - the heating coil. Low resistance, means more energy can get to the juice and therefore produce thick powerful clouds when using something as simple as an unregulated mechanical mod without variable wattage.
This explains why the variable watt box mods that you are beginning to see more and more frequently are selling quickly. They have the capacity to create great clouds, or small ones, have an element of variable control - but also they house an 18650 battery, which gives a pretty good usage life between charges.
If you want to check them out, we have them on display to play with in our new ecig shops in Clacton, Enfield, Canterbury and our Southend Vape Shops.