Creative Cloud Connection preview is an app that runs on your computer. It allows you to easily manage your files on Creative Cloud. It doesn’t require using the Creative Cloud website to upload or download files.
Once installed, it creates a local folder on your computer whose content match everything stored on your account on the Creative Cloud Files page. When first launched, the app downloads any files you had previously uploaded to Creative Cloud. From there, the app automatically syncs content between the two when running. Any files or folders you place into the sync folder locally are automatically uploaded to Creative Cloud website. And, files removed locally are automatically removed online (the same is true in reverse.)