How does DNA replication work?

First, the DNA Helicase enzyme ‘unzips’ the two stranded DNA by breaking the hydrogen bonds present between the complimentary base pairs on the two opposing strands. Then this leaves two exposed strands, allowing free DNA nucleotides to each form hydrogen bonds with its complementary base on the exposed strand. DNA Polymerase then goes along and connects the free nucleotides in each strand together to form a long phosphodiester backbone. Once replication has finished, all the enzymes detach and we end with two identical copies of the DNA, each with one original and one new strand.