Nucleic acids are the polymers of nucleotides. There are two types of nucleic acid, which are Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA).
A nucleotide is made up of three components, which are a pentose sugar, a nitrogenous base, and a phosphate group. On the other hand, a nucleoside is made of two components: pentose sugar and nitrogenous base; that is why nucleotide is called a phosphorylated nucleoside.
The nitrogenous base is joined to the sugar molecule by a glycosidic bond and forms a nucleoside structure. The nucleoside combines with a phosphate group by an ester bond to form a nucleotide. The nucleotide is acidic because of the presence of the phosphate group in them.