as far as I know...
Atomizer - Device you drip juice directly into then vape
Cartomizer - An atomizer in a cartridge containing filler for wicking and juice. Can't see how much juice you have left.
Clearomizer - An atmoizer in a clear or opaque tank that uses, quite literally a wicking system (i.e. there are wicks and you can clearly see them). On the clear tanks you CAN see how much juice you have left.
Carto-tanks - A cartomizer in a tank. Like a regular cartomizer, but with holes punched in it to leech the juice from the tank it sits inside of. Tanks are usually clear so you CAN see how much juice you have left.
For carto-tanks you can get "blank" cartomizers, meaning they have no juice in them. You can also find them pre-punched, or get a hole puncher for them.
Clearomizers are designed to work right out of the box, but as some of us have found your results may vary. Many clearos feature replaceable heads.. meaning when the atomizer coil is burned out or badly gunked up (burnt taste), you replace the whole head, which has the coil and the wicks.
Some clearos have "rebuildable" heads, meaning if you have a little DIY spirit, you can buy the wire that makes up the coils, some wicking material and "roll your own" heads and do it on the cheap.
For carto tanks, when the thing starts tasting burnt or quits firing, you simply replace the cartomizer. Carto tanks can have better flavor or vapor than the clearos, and bigger tank capacity, but there's no "rebuilding" them.
Hope that helps.
*edit* Also, I am a slow typer
