A whitewall tire is a regular tire that has a white stripe on the side. It's kind of like when you draw a line on your toy car tires with a white crayon. This stripe is usually about an inch wide and goes all the way around the tire. It can make the tire look fancy and old-fashioned.
The white stripe used to be more popular in the past because it made cars look cooler and more stylish. But today, most people just use regular black tires because they are cheaper and more practical.
Sometimes, people still use whitewall tires on classic cars or custom cars to make them look extra fancy. It's like wearing a fancy hat or jewelry - it doesn't really serve a practical purpose, but it makes the car look extra special.
Overall, a whitewall tire is just a regular tire with a white stripe on the side that makes it look fancy and old-fashioned.