Here's how it works:

* DNA polymerase reads the existing DNA strand as a template.

* It then adds complementary nucleotides (A with T, C with G) one by one to the growing new strand.

* It uses a chemical reaction to form a phosphodiester bond between the sugar-phosphate backbone of the existing strand and the new nucleotide.

There are several different types of DNA polymerase, each with specific roles in DNA replication and repair.