The term "en-US" refers to the English language as it is used in the United States. It is a specific locale code that helps software and websites display content in American English, which includes unique spelling, vocabulary, and grammar rules compared to other English dialects, such as British English. In computing, "en-US" is often used in programming and web development to ensure that applications cater to American users. This can affect everything from date formats to currency symbols, making it essential for businesses targeting the U.S. market to provide a localized experience for their customers.