Regulated mods allow you to control the voltage, the wattage, or both.
Mechanical mods uses power directly from the battery with no control over the voltage or wattage. These are generally used for rebuildable dripping atomizers and rebuildable atomizer tanks. The wattage can be regulated in mech mods when inserting a kick.
You MUST be experienced with mechanical mods and sign a waiver to purchase!
RBA - rebuildable atomizer (coil)
RDA - rebuildable dripping atomizer where you drip e-liquid directly on to the wick/coil a few drops at a time. Most often used for sub-ohm vaping.