http://www.komando.com/happening-now...rticle_0-title
excerpt:
"Those older versions of Windows would dump stuff on your computer's hard drive, if it was running out of RAM. The problem there is that retrieving stuff you need from the hard drive is a slow process.
Now, with Windows 10, Microsoft is keeping more of the things you save in your computer's memory, which is much faster than the hard drive. It's doing that by compressing files."
