The Partition Cache Wipe is a bit like deleting the cache and cookies on a PC or laptop. Cache files are tiny bits of information that can help some apps load a more quickly. Like clearing your cache and cookies on a computer, deleting these files doesn't hurt anything and you won't lose any personal information by doing so.
Corrupt cache files can keep internet websites or apps on your phone from loading, they can cause your device to slow down or feel a bit warmer than normal. Clearing them may fix these issues. Many Android sites also suggest performing a partition cache wipe after a system update.
Please follow the troubleshooting steps below:
Turn off the device.
Press and hold the Volume Up key, Home key, and Power key at the same time.
When the phone powers on, the Android System Recovery screen appears approx. 30 seconds later.
Release all of the keys.
Press the Volume down key to highlight "wipe cache partition."
Press the Power key to select.
Press the Volume down key to highlight “yes” and press the Power key to select.
When the wipe cache partition is complete, “Reboot system now” is highlighted.
Press the Power key to restart the device.
This works a bit differently on the Galaxy S8: instead of the Home button, you'll hold down the Bixby button, Volume Up and Power buttons at the same time. The rest of the process is the same.