Which protocol allows Linux or Unix servers to host files for Windows clients?

Samba is the correct choice for enabling Linux or Unix servers to share files with Windows clients. This protocol implements the SMB (Server Message Block) protocol, which is natively used by Windows for file sharing, printer sharing, and network browsing. By using Samba, Linux or Unix systems can seamlessly communicate with Windows systems, allowing them to share files and resources across differing operating systems.

The importance of Samba lies in its ability to create a bridge between different operating systems, enabling users on Windows clients to access files hosted on a Linux server as if they were on their own machine. Samba also provides comprehensive support for Windows authentication, making it easier to manage access to shared resources.

Other options such as NFS (Network File System) are primarily used in Unix/Linux environments for sharing files among Unix/Linux systems, but they do not provide native support for Windows clients. FTP (File Transfer Protocol) is used for transferring files over a network but does not provide seamless integration with Windows file sharing, and HTTP (Hypertext Transfer Protocol) is primarily used for serving web content and not specifically designed for file sharing between different operating systems. Therefore, Samba stands out as the most suitable protocol for this task.