How to clean the Memory in Samsung Galaxy S8+?

You can stop apps from running in the background and delete unnecessary data, such as cached, temporary files.

Navigate to Apps screen → Samsung Folder → Samsung Members → RAM and Storage icon → FREE UP NOW 

Pictorial representation of the above settings are as follows :  

a). From home screen, swipe up to launch Apps.

b). Tap Samsung.

c). Tap Samsung Members.

d). Tap RAM & Storage icon.

e). Tap FREE UP NOW.

f). It will take some time to clean RAM. It will take some time to clean Storage.

CLICK HERE to know how to manage Community in Samsung Galaxy S8+ ( SM-G955 ).