Cytidine is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ribofuranose) via a β-N1-glycosidic bond. Cytidine is a component of RNA.
If cytosine is attached to a deoxyribose ring, it is known as a deoxycytidine.
Read more about Cytidine: Dietary Sources of Cytidine, Cytidine Analogs