So we basically have the target DNA molecule that we want to replicate, we have the pairs of DNA primers, we have the heat resistant DNA polymerase and we also have the different types of deoxyribonucleotide triphosphate. So let's begin with step one. In step one, what we actually want to do is we want to increase the temperature so that we reach a temperature where the hydrogen bonds will break between those two DNA strands. So what we want to do is we want to separate the two strands of DNA. So let's suppose this is the DNA molecule, our target DNA molecule, and this intersection is basically the target sequence. It's the sequence of nucleotides that we want to replicate.