Diapers are like big underwear for babies who can't go to the potty on their own yet. They are made of special materials that can absorb pee and poop so that it doesn't get all over the place.
To put on a diaper, you first lay your baby on their back on a clean surface. You then take the diaper, place it under their bottom, and bring the front part up between their legs. You then fasten the sides with tape or velcro to keep it in place.
When your baby has gone pee or poop in their diaper, it's time to change it. You take the dirty diaper off by unfastening the tabs and gently lifting your baby's legs up. You then use baby wipes to clean them, making sure to wipe from front to back for girls so you don't spread germs. After they're all cleaned up, you put on a new diaper just like before.
It's important to change your baby's diaper frequently, about every 2-3 hours, so they stay clean and dry. And always make sure to wash your hands after changing a diaper!