For iPhone and iPad users who still connect their devices to a Mac for syncing and backups (and there are a lot of people who still do this), there are changes in the latest version of the Mac operating system. In macOS 10.15 Catalina, the iTunes app is gone.
Now you use the Finder, similar to how you see a hard drive or a server. Here’s how to use your device in the Finder and how to back it up.
Your iOS device in the Finder
When you connect your iPhone or iPad to your Mac using a Lightning cable, it will appear in a Finder window. In macOS Catalina, your device is in the left column in the “Locations” section. (If this is the first time you are connecting the Mac and iOS device, you will be asked to pair the two on the Mac, and you’ll have to trust the Mac on your iOS device.)
When you click on your iOS device in the left column, the window will fill with some information that looks a lot like the info you used to see in the iTunes app.
Read more at MacWorld.com