Back in the 1990s, Microsoft developed a protocol that allows one Windows machine to access the files and folders on another Windows machine. The protocol, which is known as the Common Internet File System (CIFS) – but was originally called Server Message Block (SMB), has been implemented on other operating systems including Linux. The most popular implementation is known as Samba and it allows devices like the Raspberry Pi to act as a CIFS file server. To put it another way, it allows a Windows PC to mount a folder on a Raspberry Pi and then copy, delete, read and write files on the it.

Installing and configuring Samba on a Raspberry Pi for basic file sharing is quite simple. …

Full article here:
How to Turn Your Raspberry Pi into a File Server Using Samba (Make Tech Easier)