What are the main similarities and differences between DNA and RNA?

-DNA and RNA are very similar in their molecular structure. Both of them are formed by smaller units called nucleotides. A nucleotide is composed by 3 parts: a sugar group, a phosphate group and a nitrogenous base. Nucleotides form chains by linking their “phosphate group” to the “sugar group” of their neighbouring nucleotide, forming what is known as “sugar-phosphate backbone”.
-The first and obvious difference is that DNA is formed by the nucleotides Adenine, Guanine, Thymine and Cytosine, while RNA has Adenine, Guanine, Uracil and Cytosine. The second difference is in functionality: DNA is mostly used to store genetic information of organisms. This is because, DNAs tends to adopt a highly stable and long-lasting form where 2 chains that are complementary and antiparallel form a double-strand (similar to how the 2 sides of a zipper zip together). On the other hand, RNAs are more fragile and adopt structures with associated functions that are essential for survival, such as protein translation.