FreeNAS is a free, open source, Network-Attached Storage operating system based on FreeBSD.
Network-Attached Storage (NAS) is a computer attached to a network that is dedicated solely to providing data storage for other devices on the network. This is often done either to save space, increase storage space cheaply, or provide convenient file-sharing.
FreeBSD is a free, open source Unix-like operating system. It is noted for being one of the most reliable unix-like systems. To learn more about FreeBSD, visit FreeBSD.org.
FreeNAS uses a custom version of FreeBSD and a web-based interface to provide a fully-featured NAS environment. FreeNAS offers software-based storage and backup solutions for a variety of applications, from home to enterprise.