Do average folk actually do the defrag cleaning? I know how to, but have done it exactly twice in over 20 years of owning computers. Of course, I clean my toaster about once year, so maybe that's just me.
OT
"De-fragging" was much more important in the early days when PC's had smaller hard drives and slower CPUs.
With such very large hard drives these days and very fast CPUs, it has become not as critical as it once was, since there is usually plenty of new unused space available on the hard drive, and the new PCs have very fast CPUs to get to that space.
I personally don't do it anymore either, but the theory is that it could speed up your PC and give you more contiguous free space if it is properly defragged. Especially on older PCs it could help it.
JMO
My understanding of what "de-fragging" does is it takes the small "chunks" of available space that were freed up by previously deleted files, etc.., and scoots them all together to form "larger chunks" of free space for the PC to use. It also physically moves the indexing around to allow the hard drive to write to that space quicker.
So instead of having your hard drive lazer pointer having to keep scooting back and forth all over the drive, it can just go directly to the new larger free space chunks.
With the lightning speed of new PCs and the tremendous amounts of free space on the hard drives, it is not as noticeable as it once was, and not as critical as it once was. My new PC is TERA-BYTE hard drive. ....LOL
Also, not to scare anyone, but defragging is a somewhat dangerous thing IMO because it truly does re-organize file structures and physically moves file pointers around. If properly done, it is fine.
But the thing scares me. LOL We have lots of electrical issues where I live and what scares me is losing power in the middle of a defrag process...LOL