This is a good tool for visualizing your raid needs from your capacity and total number of drives.

https://www.seagate.com/products/nas-drives/raid-calculator/

I’ll preface that I’m no raid expert, just a nerd that uses it occasionally.

The main benefit of most raid configurations is the redundancy they provide. If you lose one drive, you do not lose any data. It’s kinda obvious how you can have 1:1 redundancy, you just have an exact copy of the drive. But there are ways to split data into three chunks so that you can rebuild the data from any two chunks, and 5 chunks so that you can loose and two chunks. Truly understand how raid does this could easily be an entire college course.

Raid 0 is the exception. All it does is “join together” a bunch of drives into one disk. And if you lose an individual disk you likely will lose most of your data.

Another big difference is read/write speed. From my understanding, every raid configuration is slower to read and write than if you were using a single drive. Each raid configuration is varying levels of slower than the “base speed”

I typically use raid 5 or 6, since that gives some redundancy, but I can keep most of my total storage space.

The main thing in all of this is to keep an eye on drive health. If you lose more drives than your array can handle, all of your data is gone. From my understanding, there is no easy way to get the data off a broken raid array.