In macOS Catalina, iTunes has been replaced by separate apps, but none of those new apps takes on the tasks of syncing your music, books, photos and other data to your iPhone, iPod touch or iPad. That responsibility now falls upon the Finder.

So, does this means you can plug in your iPad and drag and drop all your apps’ files between it and your Mac? Of course not. In fact, apart from this functionality now being in the Finder, not much has changed at all.

How much space do duplicate files take up on your iPad? In theory, they use no extra storage. Thanks to the design of the Apple File System (APFS) used on iOS and macOS, duplicating a file doesn’t actually create a copy. It just creates a reference that points to the original file on the disk.

But what about File Providers, and iCloud, and all that stuff? I decided to take a deep dive and find out if you can really make a zillion copies of a file with no penalty. The results were, to say the least, confusing.