Here's a breakdown:

* Nucleic acids are polymers made up of nucleotides.

* Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base.

* Phosphodiester bonds form between the phosphate group of one nucleotide and the sugar of the next nucleotide. This creates a chain of nucleotides, forming the backbone of DNA and RNA.

Let me know if you'd like more detail on any of these points!