The main difference is the type of sugar that can be found in the DNA and the RNA. The sugar in DNA is called Deoxyribose, while the sugar that can be found in the RNA is called sugar ribose. The ribose contains one -OH more than the Deoxyribose. Aside from the sugars that can be found in the DNA and RNA, they also have some differences that you should know.
The DNA is responsible for storing and replicating different genetic information, while RNA can be used to build various proteins before they can be moved to the ribosomal protein factories. The DNA also comes in two strands while the RNA also comes in one strand.