▼ Replication of DNA process, I have seen in the animation

 There are many terms they used to tell you how this mechanism of DNA strand unwinding itself and elongate itself to become two different strand at the end.

What do you mean strand?

DNA is double helix, like you see it on the most right. One becomes 2, remember I Ching, 2 becomes 4? So first you have to be able to unwinding this one original DNA strand. 

So when you open up that double helix, that is two strand?

Yes.

You make 4 strands at the end?

Technically you see 4, yes. You just adding 2 more strand on the opposite of each other parenting strand.