As a result of DNA replication two DNA molecules come into existence. Why is it not correct to assert that two "new" DNA molecules are created? What is the name given to the process concerning that fact?
During replication every chain of the DNA molecule acts by pairing new nucleotides and after the process two newly formed chains made with the union of these nucleotides appear. Then two DNA molecules are formed, each with one chain from the original molecule and one new chain created by new nucleotides. Thus it is not completely correct to assert that the replication forms two new molecules of DNA. It is better to affirm that two new half-molecules are formed.
For this phenomenon DNA replication is called semiconservative replication.