Insert pads are designed to be worn with regular underwear. They are cost-effective, very absorbent and easier to carry with you and replace while you are "out and about."
Insert pads are specifically designed to present a dry surface to the skin. Do not use sanitary pads for incontinence - they tend to stay wet and could irritate your skin.
With the exception of booster pads, all insert pads are designed for use by themselves. Use only booster pads to increase the absorbency of another product. If you would like your favorite pull-ups or briefs to last longer, you can put a booster pad inside them.