OK, you seem new to RAID. A RAID 5 or RAID 6 array will stripe the data across all disks. This means that each disk holds some of the data. There is also some redundant error checking data which can re-create the data lost if either 1 or 2 disks go missing. So, RAID5 or RAID6 allows you to recover from one or two failed disks. However, it also means complete loss of all data stored on the array when you go above these disk failure levels.
A RAID controller will generally flag a disk as failed if it doesn't respond properly within a certain time limit. Once it is flagged as failed it must be treated just like a disk that did actually fail. Enterprise drives are built with this in mind and will respond within a reasonable time limit. Cheap home drives are not and they may cause timeouts and disk failures to appear.
There are 3 general types of RAID systems. You can have an add-in RAID card, the operating system do the RAID or the motherboard and BIOS do the RAID. Generally, I've listed these in order from best to worst. In some cases, the add-in RAID card is a piece of crap. Windows doesn't do software RAID.
So, you have to decide. Do I place all my data into a system where either 2 drives or 3 drives fail and I've lost it all? Do I find an alternative that will at least leave me with data on my remaining good drives even if 2 or 3 drives fail?
I personally see no good reason for using a RAID5 or RAID6 array at home. I'm running an unRAID server and copy my important data to an external drive I keep off-site.
Good luck with your decision.