The number "410" can refer to several things, but it is commonly known as an HTTP status code. Specifically, a 410 status code indicates that a resource is no longer available on the server and that this condition is permanent. Unlike a 404 error, which means a page is not found but may be available again, a 410 error signals that the content has been intentionally removed. In addition to its use in web development, "410" can also refer to the area code for parts of Maryland in the United States. This area code covers cities such as Baltimore and Annapolis, providing telephone services to residents and businesses in the region.