Unraid IS NOT RAID. Each disk is an independent filesystem, there is no striping. 1 (or 2) parity disks provide redundancy to allow 1 (or 2) disks to be rebuilt from all the other disks using the parity calculation.
Since each disk is an independent filesystem, each file is completely contained on a single disk, and each disk can be read on any linux if needed. Also, independent disks allows Unraid to mix different sized disks in the array, and to easily replace or add disks without rebuilding the array.
Even though each file is completely contained on a single disk, Unraid allows folders to span disks (User Shares).
Unraid is a standalond OS and it can also host VMs and dockers. There are hundreds of docker applications available that will let you do what you want and much more.
See the Product pages linked at the top of this page and this Wiki Overview for more details:
https://wiki.unraid.net/UnRAID_6/Overview