* Building blocks: Both are nucleic acids, meaning they are polymers made up of nucleotides.

* Nucleotides: They are both composed of three parts:

* Sugar: DNA has deoxyribose sugar, while RNA has ribose sugar.

* Phosphate group: The phosphate group is the same in both molecules.

* Nitrogenous base: Both have the same nitrogenous bases: adenine (A), guanine (G), and cytosine (C). DNA also contains thymine (T), while RNA contains uracil (U).

* Function in genetic information: Both play a crucial role in carrying and transmitting genetic information. DNA stores the genetic blueprint of an organism, while RNA is involved in the translation of that blueprint into proteins.

* Base pairing: Both use complementary base pairing, where adenine (A) always pairs with thymine (T) in DNA or uracil (U) in RNA, and guanine (G) always pairs with cytosine (C).

However, they also have crucial differences, which are important for their distinct functions.