So firstly DNA replication is a semiconservative process which means that once we form our new DNA one of the single stranded DNA molecules is the new synthesized one and the other one comes from our original DNA molecule that we used as a template. So for example, if we have a single DNA molecule and it undergoes DNA replication we essentially form two DNA molecules and each one of those two DNA molecules contains one new synthesized strand and one original parent strand that came from the original DNA molecule. And this is what we mean by a semiconservative process. Now once the proteins, once the group of proteins binds to the DNA molecule at the point of origin replication proceeds on both strands but it takes place in opposite direction. So to see what we mean let's take a look at the following diagram. So let's suppose we have the original DNA molecule shown.