Simple Date Filter

Hello,
I wish to make this excel document:

1-I enter a list of urls in the first collum

2-I enter a different list on the second collum

3-The third collum gives me the list that does not appear in the first one

After that, I copy the third collum list to the first one, to update it.

Can somone please tell me how to or link me to some tutorial?

I searched for hours but I just don't know what its called so i keep getting other tutorials...
Thanks!