What does it mean to receive a user's news feed?

[Low Rate Rest]

In Privacy settings, there is an option to allow which users to receive your news feed. What is "my" news feed?
Sorry for the newfag question, but I only now consciously notice this setting in Xenforo.

 

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[Book Thief]

Apparently it's related to users you're watching, allowing you to know what other users are posting and rating others' posts.

You can check your news feed by clicking at the top:

In other words, it's fairly useless.