* DNA (Deoxyribonucleic acid): DNA is the genetic material found in all living organisms. It carries the instructions for building and maintaining an organism.

* RNA (Ribonucleic acid): RNA is involved in protein synthesis and other cellular processes. It acts as a messenger between DNA and ribosomes, where proteins are made.

Both DNA and RNA are long chains of nucleotides linked together by phosphodiester bonds. Each nucleotide consists of a sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and a nitrogenous base.