Some people may initially think that DNA and mRNA are the same, but actually, these are two different things. DNA means deoxyribose sugar, while mRNA is composed of the ribose sugar. DNA is known to be present in the nucleus of the cell, while the mRNA usually goes to the cytoplasm after the synthesis.
DNA contains the available details, while mRNA usually acts as the intermediary between the information that can be found in the DNA and the acid sequence that can be found in proteins. Another difference is that the DNA is known to be double-stranded while the mRNA usually goes into the cytoplasm after synthesis has taken place. They also have some similarities, one of which is the fact that both DNA and mRNA come with phosphate backbones.