Okay kiddo, let's talk about accents! Sometimes people sound different when they speak, and that's because of things like where they grew up or what language they learned first. Two big kinds of accents are called rhotic and non-rhotic.
In a rhotic accent, people say the "r" sound at the end of words that end in the letter "r." So instead of saying "cah" for "car," they say "car" with a clear "r" sound at the end. This is often heard in places like the United States, Canada, and Scotland.
In a non-rhotic accent, people do not say the "r" sound at the end of words that end in the letter "r." So instead of saying "car" with a clear "r" sound at the end, they might say something more like "cah." This is often heard in places like England, Australia, and some parts of the United States like Boston.
So to sum it up, rhotic accents say the "r" sound at the end of words that end in "r," while non-rhotic accents do not. It's just one of the many ways that people can speak differently based on where they come from!