A hubcap is a removable cover that fits over the center of a car's wheel. If you look at most cars, you'll see either shiny metal wheels or plastic covers with designs on them. Those covers are hubcaps. They snap onto the wheel to protect the parts inside and make the car look nicer.

Originally, hubcaps served an important practical purpose: they kept dirt, water, and road debris from damaging the wheel's hub and bearings. Early cars needed this protection because exposed metal parts would rust or wear out quickly. Over time, as wheels became better sealed, hubcaps became more decorative than functional.

You've probably seen hubcaps lying on the side of highways. They can pop off when a car hits a big pothole or takes a sharp turn too fast. Some people collect vintage hubcaps from classic cars, especially chrome ones from cars of the 1950s and 1960s. Others replace lost hubcaps with mismatched ones, which is why you sometimes see cars with four different hubcap designs.

Modern cars often skip hubcaps entirely, using alloy wheels (wheels made from aluminum or other metals) that look good on their own without needing a cover.