The majority of e-cig tank (also called clearomizers and atomizers) have replaceable coils (also known as coils heads, atomizer heads, burners, etc).
Coils are heating elements which heat the liquid in the tank, and they are heated by the power in the battery.
They often come in a choice different electrical resistances which you will see expressed as an Ω or Ohms rating, such as 1.8Ω, 0.5Ω, etc.
The choice of ratings allows users to fine tune their vaping experience.
Ohms is a measure of electrical resistance, it refers to how freely or not an electrical current is able to travel. If it passes freely there’s less resistance, if it can’t travel so freely there’s more resistance.
It's the same principle as water running through a pipe, if you make the pipe smaller but there's still as much water the resistance will increase as it can't travel as freely as it did running through the bigger pipe.
There are two things that determine the speed of heating and how hot the coil head gets, which is the battery voltage (voltage is electrical pressure) and the Ohm rating of other parts attached to the battery.
Below is a general guide of two similar coils (with lower and higher Ohms ratings) listing their differences, advantages and disadvantages, depending on how you look at it.
So as you can see there are pro's and con's whichever way you look at it, and if you're still not sure what you should be doing, just bear in mind that there’s no definitive answer, there’s no right or wrong choice as such, much of this comes down to personal preference plus differences in equipment and e-liquid.
E-LIQUID / JUICE INFO
COILS / ATOMIZERS
E-CIG TANK PROBLEMS
E-CIG BATTERY HELP
SUB OHM BASICS