A vendor is someone who sells goods or services.

You see vendors everywhere: the person selling hot dogs from a cart on the sidewalk is a street vendor. At a farmer's market, vendors set up tables displaying fresh vegetables, baked goods, or handmade crafts. When your school needs new computers, the principal works with technology vendors who supply equipment to schools and businesses.

The word emphasizes the selling relationship. A bakery is a business, but when that bakery sells cupcakes to your school for a fundraiser, it becomes a vendor to the school. Large companies often work with dozens of vendors who supply everything from office supplies to raw materials for manufacturing.

Vendor sounds more formal than seller. You wouldn't call someone at a garage sale a vendor, but you would use the term for someone operating a regular business selling goods or services. At a baseball stadium, people walking through the stands shouting “Peanuts! Popcorn!” are vendors. At a carnival or fair, vendors run game booths and food stands.

The word can also appear in compound terms like vending machine, which is a machine that vends (sells) snacks or drinks when you insert money.