Average Engagement: The average daily number of times people engaged with your page by clicking on any of the content without generating a story.
Average People: The average daily number of unique people who engaged with your page by clicking on any of your content without generating a story.
Average Stories: The average daily number of stories created about your Page.
Average Page Views: The average daily number of Page views.
A Story is an item that appears in a user’s newsfeed when their friend interacts with a Page or its content. E.g. “Jake commented on a post from Locowise.”
The following actions can generate stories:
liking a post
liking a comment
commenting on a post
commenting on a comment
sharing a post
answering a question/”poll”
responding to an event
claiming an offer
posting on the page wall
mentioning the page in a post
tagging the page in a photo
checking in at your place/page
sharing a check-in deal
liking a check-in deal
writing a recommendation
liking a page
For more information on Facebook metrics, please refer to the following FB developer resource: https://developers.facebook.com/docs/graph-api/reference/v2.8/insights