What do the OneDrive Icons mean next to Files\Folders?

When using OneDrive, files can have a number of statuses.

Look to the right of a file and you will see these for Icon

The file\folderFile is available in the cloud and can be accessed but your device must be connected to the internet

The file\folder is on your local PC and can be accessed even if you are not connected to the internet
You have requested that this file\folder is always kept on your local device
This means that the File is currently Syncing, because you have updated it, or someone else has.
IF attached to a folder, it means items within are being Synchronized

Look at this guide to free up space on your hard drive or keep files local How to Free Space on your Hard Drive or Keep Files Local all the time

Managing Files using Microsoft Storage Sense Click here