First of all a base coat or base, is to a varnish to apply as a base, before the nail polish, usually colored. The latter will protect the nail from the varnish because it has anti-yellowing properties, it hardens the nail and prolongs the duration of the varnish.
The top coatwill fix the varnish, dry it faster and hold the manicure longer. The rendering with a top coat is brighter than without its use. In addition, it can be colored or glittery.
You should also know that 2-in-1 products serving as both a base and a top coat exist. The latter are both economical and practical.
We recommend that you use the adequate manicure and pedicure set to take care of your nails before applying any decoration on your nails.