Resetting your Windows 8 PC goes like this:

1. The PC boots into the Windows Recovery Environment (Windows RE).
2. Windows RE erases and formats the hard drive partitions on which Windows and personal data reside.
3. Windows RE installs a fresh copy of Windows.
4. The PC restarts into the newly installed copy of Windows.

Refreshing your PC goes like this:

1. The PC boots into Windows RE.
2. Windows RE scans the hard drive for your data, settings, and apps, and puts them aside (on the same drive).
3. Windows RE installs a fresh copy of Windows.
4. Windows RE restores the data, settings, and apps it has set aside into the newly installed copy of Windows.
5. The PC restarts into the newly installed copy of Windows.