I'll demonstrate the base coat - rich filler base coat and a regular base coat. As a matter of fact, no, this isn't a regular base coat. It's a rehydrating base coat. What it'll do is it'll rehydrate the nail if it's dry. Of course, it's going to stop your natural nail from turning yellow if you're using a dark polish. I'll show you the rich filler first.
The rich filler's always milky, but it should always look thin and almost translucent as you apply it. If you've applied too much it'll look really thick and clumpy, then it'll take the nail polish even longer to dry. As you can see it's going on nice and clear just with like a little pinch of a milky finish. Whenever you're applying base coat apply it the same way you would polish, three strokes, and always seal the free edge. That'll avoid the nail polish from chipping too soon. You apply base coat to all 10 nails. By then it'll dry because it's thin. Then you can go on with your two layers of nail polish.
I'll show you the rehydrating base coat next. Always remember it should be thin, because you want it to dry fast enough so that when you get to the polishing segment of your manicure that you're doing at home it's dry. So, that's rich filler which actually dried matte. You'll see that this one as it's drying may leave a little bit of a gloss but not a big enough gloss where you think it's top coat. That's the difference. Base coat goes on the bottom to protect your nail and form a barrier between your nail and the nail lacquer or nail polish whichever name you prefer.
If you're in a rush use, the combination top and base coat. This way you're not looking for the other bottle. It's also great to use if you're running out the door and you just want to give your nails a natural gloss look. You can apply two coats and it'll dry fast. You'll look like you have a manicure.