An RDA stands for Rebuildable Dripping Atomizer. An RDA is a type of RBA that requires the user to manually add juice on the coils and wicks, instead of being fed from a tank. RDAs have a juice well at the bottom of the build deck to hold e-liquid, and the wick tails are placed into the well. Generally, the juice well does not have as much capacity as a tank, so the vaper must continuously add e-juice ever so often, to prevent the wicks from getting dry.
The manual nature of wetting the wicks and coils makes RDAs less convenient than a tank, unless they’re set up for and used with a squonk mod. A squonkable RDA can be fed e-juice from a small squeezable bottle located in the mod, accessed through a small window. Squonking is still manual and it’s like dripping, except that it’s much more convenient than having to carry an e-juice bottle separately.