The idea behind it is simple, actually. Whenever you need to use a service that uses an app, but you don’t have it downloaded already, your iPhone downloads a small part of it first. This small part comes with the feature you need to make use of the service. And because it’s only a small part of the main app, they will be less than 10MB in size.
And they look like they will be pretty accessible too. Apple is making it so that with iOS 14, you can get App Clips from the web, from messages, or from a place card in Maps. More traditionally, you can get them from NFC tags and QR codes. Furthermore, Apple is coming up with its own App Clip code, which combines the qualities of both. Apple also says App Clips won’t clutter your iPhone’s home screen. You can still find them in your App Library, and download them from the App Store if you want to keep using them. (Source: Apple)
