Selective Synchronization is a feature that allows users to choose specific files or folders to sync across their devices, rather than syncing everything. This is particularly useful for managing storage space and ensuring that only the most important data is available on all devices.

In the Apple ecosystem, this concept is closely related to iCloud Drive's "Optimize Mac Storage" feature, which automatically manages the storage of files between your Mac and iCloud. However, for more granular control, users can manually manage their iCloud Drive files or use third-party applications that offer selective synchronization capabilities.

Examples:

1. Using iCloud Drive:

   • Step 1: Open the Finder on your Mac.
   • Step 2: Click on "iCloud Drive" in the sidebar.
   • Step 3: To manually manage files, drag and drop the files or folders you wish to sync into the iCloud Drive. To remove files from local storage but keep them in iCloud, right-click the file and select "Remove Download."

   # Example of moving a file to iCloud Drive via Terminal
   mv ~/Documents/important_file.txt ~/Library/Mobile\ Documents/com~apple~CloudDocs/

2. Using Third-Party Applications:

   • Step 1: Download and install a third-party application like Dropbox or Google Drive from the App Store.
   • Step 2: During the setup process, choose the folders you want to sync selectively.
   • Step 3: Use the app's settings to manage which files and folders are stored locally and which are only available online.

   # Example of using rsync for selective synchronization
   rsync -av --exclude='*.tmp' ~/Documents/important_folder/ ~/Dropbox/important_folder/