Describe DNA replication in details?

Replication :  DNA replicates itself by first breaking the hydrogen bonds between the nitrogen base pairs, and "unzips" itself into two strands. A replication fork, a Y-shaped structure, moves down the strands as DNA unzips.

Complementary nucleotides, which are floating free in the nucleus, form hydrogen bonds with each separated DNA strand at their matching nucleotide sites according to the base-pairing rule. In this way,

DNA replication is a semi-conservative process whereby each half of the original DNA strand builds a new complementary strand on itself. DNA polymerases catalyze the formation of sugar to phosphate bonds of the nucleotide monomers to complete the building of a new strand on the original strands.

Replication takes place at a very fast rate. In the bacterium E. coli, the complex makes DNA at over 1000 base pairs per second, and makes mistakes in the order of perhaps one base in a billion to one per trillion. In bacteria, there is just one point where replication begins, but in eukaryotes there are many specific origins for replication. Replication can proceed in both directions from an origin.