Originally Posted by
CliftonGK1
"Dry" lubricants are lighter weight lubes, often containing an evaporative carrier with teflon. Apply it lightly, run it in on the stand to penetrate the rollers, wipe it clean and you get a chain that doesn't have a gloopy coating of stuff on it to pick up a lot of dirt, dust, and grit (although, as ItsJustMe pointed out, if you ride in really dirt/dust prone conditions then almost nothing will solve it totally.)
"Wet" lubricants are high viscosity and coat everything with a protective barrier of gloop. Great for super muddy MTB and CX courses, commuting in the rain or snow (unless it's super-duper-cold) or any conditions where your chain might see prolonged exposure to water. The downside is that wet lubes suspend particles of everything, eventually turning a wet lubricant into a grinding paste if you don't thoroughly clean and relube frequently.
You've got it backwards. Dry lubricants are higher molecular weight ('heavier') lubricants like waxes that are dissolved in a solvent which may, or may not, contain other additives. Once the solvent evaporates, the heavier lubricant stays in place and won't flow out of the interior of the chain. The reason it doesn't pick up dirt and grit is because there is nothing to stick to. It also isn't self replenishing...i.e. doesn't flow out of the interior of the chain to replace lubricant that is worn away.
Wet lubes are lower viscosity oils that are also dissolved in a solvent. They coat everything and readily flow out of the chain's interior. They are self replenishing but they are also thin enough that contaminants get trapped in the oil coating.
For dry and dusty conditions, dry lubes like White Lightning are ideal.