Definition Common Internet File System(CIFS)

Common Internet File System(CIFS) is a network communication code of behavior for providing shared access to files, printers, and serial ports between nodes on a network. It also provides an authenticated inter-process communication mechanism.

The CIFS protocol allows files and folders to get transferred between servers and clients. Here we explain what CIFS is and what you can do with it.

What is Common Internet File System?

CIFS is the abbreviation for the network protocol Common Internet File System.

We can use it to transfer files and folders according to the client-server principle.

It works either locally or remotely using the Internet’s TCP / IP protocol.

In addition to file and printer sharing, CIFS also provides services such as Windows RPC.

CIFS is a free and expanded version of the SMB protocol developed by Microsoft.

The protocol also supplements Internet protocols such as the Hypertext Transfer Protocol (HTTP) to transfer files more conveniently than with the FTP protocol.


If you have a server in your network whose folders and files you access from Windows, the CIFS get used. You can also see this if you use a Synology server and log into the user interface:

The client (Windows) directs its requests for specific files to the server (Synology).

The server then accepts the request and sends a response.

Note: This works similarly if the client sends a message to a program that is running on the server.

What can CIFS do?

Read and write files that are on the server.

Share files with other clients.

Restore network connections automatically if there is an error.

Use Unicode file names.

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