If you are running out of storage space on your computer and use Dropbox to store files, you can use Selective Sync or Smart Sync to select which folders save to your computer and which remain safe in the cloud. This article explains how to delete Dropbox folders from your hard drive and prevent them from automatically syncing using the Dropbox desktop app. There are two methods: Selective Sync and Smart Sync. Selective Sync lets you pick and choose which folders to sync to your local hard drive, while Smart Sync automatically moves older files to the cloud. If you require a file that has been offloaded, it will download back to your device.