Windows 10 Storage Spaces: Two-way mirror vs. parity?

I've been reading between the two and I'm still confused about how they work within Windows 10 Storage Spaces. Two-way mirror "writes data to either two disk or three disks simultaneously, so that you have multiple copies of your data (Like a RAID 1)" while parity "stripes data across the disks in the pool (like a RAID 5)". Both appears to be able to survive a single disk failure, but parity is slower than two-way in writes.

I have 3 x 5TB drives in which I want to have resiliency, and then add more drives when necessary in the future. Normally I would think two-way mirror works with two drives, but there seems to be an option for three or more drives. How does that work with odd quantity and size of drives? Given the two options, which should I go with, two-way mirror or parity?

 

Three disks mirror is probably just multiple mirrors of the same data (double redundancy). Usually RAID 5 parity won't suffer too much of a performance hit. If you have two drives, best to do mirror. If you have three, then do parity. If you have more than three, parity is your friend, as long as it has double redundancy/parity (not sure about Windows 10 parity) like RAID 6.

Honestly, unless you actually need real-time duplication, I think you're best to go with a daily or twice daily backup with some form of historical recovery like with incremental or differential backup options. RAID will just save you from a hardware failure, it won't let you recover from an accidental file deletion or data corruption.