What this is - an external USB hard drive, not a network drive (NAS).The main reason to buy - reliability. There are 2 identical hard drives inside that record the same data, so that if one fails then the other still has your data. That's what RAID technology gives you, among other things. 20% of mechanical hard drives will fail before 4 years.Compare to NAS - NAS is basically a file server on the local network. It's accessible to multiple computers and should be turned on all the time. On the other hand, this Buffalo DriveStation attaches to a single computer via USB 3 port. It turns off automatically when the computer turns off. Both use RAID technology with multiple hard drives.Compare to SSD - People think SSD is more reliable because there are no mechanical moving parts, but when left unplugged and under hot weather, the electrical charge can leak out, causing data lost. Hard drive is actually better for archival purpose, i.e., years of storage. SSD is only more reliable for shorter duration, such as less than a year.Compare to a single hard drive with cloud back up - Cloud back up is very expensive, although very reliable, because the cloud is still there if the hard drive is burned out or stolen. Transfering several TB of data to cloud storage will take days even on fast broad band. This option is only viable for small amount of data, such as less than 200GB. Clouds are also prone to computer hacks, so don't put anything there that you don't want the whole world to see.Installation - plug-and-play just like any external disk drives. Works great on my Windows 10. The utility on included disk can configure different RAID modes if needed. There are instructions for Mac, although I haven't tried. One wierd thing about the utility is that no application window shows up when it runs. To launch, right click on the Buffalo RAID utility icon in the system tray instead.Hardware - fan is nearly silent on idle and can spin up much louder on start up or when the drives get hot. The front plate can pop-out to show meanings of different color and blinking combinations of the 3 front LEDs. There's a physical off switch, which I like because hard drives last longer when they are not used frequently, and no hackers or viruses can affect a power-off hard drive.
