fallback system for when hard drive dies

view story

https://bbs.archlinux.org – looks like my hard drive on my desktop just packed up / started to make clicking noises, unable to boot it now. for back up i have always just copied my important files to a usb stick, which of course is not the best method. now i will have to buy new hard drive and re-install all over again.what is the best way to get around this problem of hard drive failure, is there a way to have 2 or n disks in desktop case so if one fails, then i can just use the spare drive. is this a RAID system or something like that.  something that keeps the disks in sync with each other, then one fails, the ot (HowTos)