Why is DNA replication called semiconservative?

DNA replication is called semiconservative because each of the two newly synthesized DNA molecules consists of one original (parental) strand and one newly synthesized strand. This mechanism preserves half of the original DNA in each of the resulting molecules. The term “semiconservative” refers to the conservation of one strand of the original DNA in each new DNA molecule, as opposed to completely conservative replication, where the original molecule is preserved intact.