There are two main types of nucleic acids:

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

* Ribonucleic acid (RNA): This plays a crucial role in protein synthesis, acting as a messenger between DNA and ribosomes (the protein-building machinery of the cell).

Both DNA and RNA are composed of long chains of nucleotides linked together. Each nucleotide consists of three parts:

* A sugar molecule: Deoxyribose in DNA and ribose in RNA.

* A phosphate group: This is the acidic part of the nucleotide.

* A nitrogenous base: There are five different nitrogenous bases: adenine (A), guanine (G), cytosine (C), thymine (T) (found in DNA), and uracil (U) (found in RNA).

The sequence of nucleotides in a nucleic acid molecule determines the genetic information it carries.