|The Simple English Wiktionary has a definition for: accent.|
An accent is the way a person speaks.
The way a person says words usually comes from where the person was a child and the other people where the person lives. People learn how to say words and sentences and so they sound the same as when others speak.
People speaking the same language can have different accents. Even people in the same country can have different accents. Sometimes people can tell what city someone lived in when as a child by the way that person speaks. One example is a New York City accent.
When first trying to learn a new language, often a person will still have the old accent. That often allows other people to guess which country or place that person lived in before.
If someone can learn another language well enough, someone may not have the old accent anymore and may get a new accent in the new language. If someone studied German in Austria, for example, people in Germany may think that person was Austrian.