NFS (Network File System) is a protocol that enables files and directories to be exchanged across a network between different systems. It was developed by Sun Microsystems and is generally used on Unix and Linux-based systems.

The NFS protocol allows a server to share its file systems with other systems in the network. In this way, users on a client system can access the shared files and directories of the server as if they were stored locally on the client system.

The process of how NFS works can be divided into four steps:

1. Sharing the file systems: The server communicates the file systems that it wants to make available to other systems in the network.
2. Client request: A client system requests a connection to the server via the NFS protocol in order to access the shared file systems.
3. Access to the file systems: After authentication by the server, the client has access to the shared file systems and can read, write and delete files and directories.
4. Disconnection of the connection: If the client no longer requires a connection to the server, it disconnects from the server.

NFS offers many advantages, including the ability to save disk space on the server as files and directories do not need to be duplicated on each client system. NFS can also facilitate collaboration between users on a network, as multiple users can access the same files and make changes at the same time.

However, it is important to note that NFS also has some disadvantages, particularly in terms of security, as the protocol does not support encryption by default. It is therefore important that NFS is used in a secure network environment and that suitable security precautions are taken to prevent unauthorized access to the shared files and directories.