As for this question, we would tackle more on its bases. Basically, RNA and DNA differ both in their backbone. Both has a phosphate backbone but the DNA has a deoxyribose backbone while the RNA has a ribose one. Also about their bases which are, by the way, nitrogenous, both RNA and DNA have similar number of nitrogenous bases which is 4. They both have 3 the same nitrogenous bases which are guanine, adenine, and cytosine. The 4th nitrogenous base for DNA would be thymine while the 4th nitrogenous base for RNA would be uracil.