Here's a breakdown:

* DNA is made up of nucleotides. These are the building blocks of DNA.

* Each nucleotide has three parts:

* A sugar molecule (deoxyribose)

* A phosphate group

* A nitrogenous base

* There are four different nitrogenous bases in DNA:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

The sequence of these four bases along a DNA strand is what carries the genetic information.