How does DNA replicate? How does the idea of base pairing used in replication?

DNA replicates typically before a cell divides. It follows a series of steps but in general DNA unzips - the base pairs that are 'exposed' are paired up with their matching 'other halves' (A-T and G-C) and you end up with 2 strands of DNA (each strand containing 1 original 'line' and one newly synthesized 'line')