Single drive unit designed for home or small office use. These units have a quad core 1.4 cpu with 1 GB RAM and are also capable of transcoding and streaming 4K H.256 Video on the fly. However we recommend them to be used for backups only as there is no data redundancy with a single drive unit. So use these units to store your backup copies of media, photos, files etc. Sometimes we even recommend attaching a separate external drive which houses a daily backup of the most important files from this unit just in case.