Explorer), and when you tried to access them they would get downloaded to your hard drive at that point, and then you could open them, copy, move, etc. The big difference is that if you used Smart Sync for all your files, the files that you currently have 'unselected', you would now designate as *online-only* - they still wouldn't be on your hard drive, but you'd be able to see their names, folders, etc. I expect that your current sync environment won't change without you telling it to. Using Rich's answer above, here is my understanding of Smart Sync: You either need to set a file or folder as Online Only, or during the installation of Dropbox you have a choice to make the entire Dropbox folder online only. It is not enabled for any files by default. it's not available to Business accounts unless you opt in to it).

Smart Sync is available on Professional accounts and Business accounts through the Early Access program (i.e. When you're done using the file, you simply mark it as Online Only again is it's removed from your computer once again. Any file you open that was set as Online Only, is first set back to Local, download to your computer and then opened just like any other file.

It allows you to browse your folders and files and open them without having to use the Dropbox website. Smart Sync is similar in that it allows you to save drive space by removing the local copy of folders and files, but the difference is that files you mark as Online Only are still visible in your local Dropbox folder on your computer.

You cannot open files on your computer in a folder that has been removed using Selective Sync.

If you need to access that folder in the future, you either re-enable it in Selective Sync and allow it to sync, or you use the Dropbox website. Unchecking a folder in Selective Sync removes it from your computer. The purpose is to save drive space by only syncing the folders you need stored locally. Selective Sync is a feature that allows you to remove folders from your local drive so they only exist in your account online. Let's start with a description of a feature you may be familiar with Selective Sync.

Dropbox smart sync review