What is RAID?

Alright, I know I'm an idiot but I still don't understand the concept well. What exactly is it and what can it be used for the common user?

first.  be it nature or nurture, there are two kinds of people in the world.  RAID 0 people, and everyone else.  the two main problems with hard drives are seek time, and throughput.  RAID 0 with 2 drives comes close to doubling throughput.

this in most applications means nothing.  there are practically no benefits from using RAID 0.  the benefits you do get, are with large contiguous reads and writes which are rare.

now as for software and hardware.  software does well in benchmarks and bombs in the real world, hardware does bad in benchmarks, but much better then software raid in the real world.

welcome to the distinction between people who like RAID 0 and the people that know better.