People from all over the world have different accents. A lot of the time, people have a different accent because they are used to speaking a foreign language, but sometimes accents come from differing dialects in different parts of a country.
What do we mean by this? For example: in the United States, English is the primary spoken language, but the way you speak may sound different depending on whether you're from New York City, California, or from the South. Those from Boston have a completely different sound to their spoken English entirely.
The diversity of English accents in the United States offers just a small scope of the accents that exist.
Those from foreign countries, including Spain, Germany, or Russia (just to name a few) will also sound different while speaking English than a native English speaker will. This is because those who are native to speaking different languages are used to pronouncing sounds a certain way, and it puts a different spin on English words.
Many studies also exist that show how accents have an impact on how someone judges you when you speak. Of course, there's nothing wrong with showing your roots in the way you pronounce your words!