Differentiate Interface Pads vs. Sponges

so so my question would be with um the interface pads do you need the interface pad if you have half inch sponges and what or if you do what's the difference between using this and this combination well there's a lot of times that this will not flatten out a rough finish right it won't fall okay right the other thing is is this if this was raw wood right right if you have knife marks all the way down you're molding yeah I've seen that a lot of times cannot get it out with even with a going to a course five inch sponge because that grain recedes I need that grain to stay more prominent but I need a little give so I'll go to the half inch interface pad and then that way I can get in and I can take out those knife marks or the milk molding marks the motor marks that you see so if I want to get a flat finish on