What are the most common types of nucleic acids?

DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid) are the two most common types of nucleic acids. Both nucleic acids are involved in carrying out cellular processes, particularly the regulation and expression of genes. 

Both DNA and RNA are made up of chains of nucleotides linked together but they are both different in structure. DNA has a double helix structure that is caused due to the hydrogen bonding between two complementary strands of DNA molecules. RNA has a single stranded structure.

DNA provides the code for all types of cellular activities, while RNA converts this code into proteins for the purpose of carrying out cellular functions.