The number of clicks (all) + ThruPlays.  Clicks (all) counts multiple types of clicks on your ad, including certain types of interactions with the ad, links to other destinations and links to expanded ad experiences, including: Link Clicks, clicks to the associated Page profile or profile picture, post reactions, comments or shares, clicks to expand media to full screen, clicks to take actions identified as your campaign objective.

Engagement Rate (All Clicks & ThruPlays)

The percentage of times people saw your ads and clicked or your video was played to completion, or for at least 15 seconds.

This metric is calculated as the total number of clicks (all) + ThruPlays, divided by impressions, multiplied by 100.

Cost per All Clicks & ThruPlay

The average cost for each engagement. 

This metric is calculated as total amount spent, divided by total number of clicks (all) + ThruPlays.