Definition of 'user-generated content apps'?

I once found a section of 'User-Generated Contents' in the Appstore guideline of apple. (https://developer.apple.com/app-store/review/guidelines/#user-generated-content)

In the case of a specific application related to a cloud service, like Google drive, how that 'User-Generated Contents' can be defined?

I mean, if a Google drive app user uploads a music file to google drive via the iOS application of google drive, will that music file be considered as 'User-Generated Contents' according to apple's Appstore guideline? Or it doesn't matter with it?

Definition of 'user-generated content apps'?
 
 
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