Both RTA’s and RDA’s are types of RBA (rebuild able atomizers). Their main benefit is that you are able to build your own coils according to your desired resistance. They serve different purposes. The main difference between them is that RTA is a tank system where as RDA is a dripper system. RDA needs to be dripped often in order to avoid a dry hit. RTA’s offer the users the advantages of RDA besides being larger in profile and able to store the vape juice.