Which part of a URL specifies the address of the server hosting the content?

The domain or server part of a URL is essential because it specifies the address of the server that is hosting the content. When you enter a URL into a web browser, the browser uses the domain to find and connect to the respective web server where the requested web resources or information resides. This domain can take various forms, usually comprised of a name and a top-level domain (TLD), such as ".com" or ".org."

The protocol indicates how data is transmitted over the internet, such as HTTP or HTTPS, but it does not specify the server's location. The file path details the specific resource or file on the server, while the query string is used to send additional parameters or data to the server for processing. However, none of these parts point directly to the address of the server hosting the content as the domain does.