Here is a list of 5 most important facebook jargon everyone should understand in order to use facebook insights:

1) “Reach”: Whenever facebook says “303 people saw your post”. It simply means that the organic reach of the post is 303.
It is important to note that not all your fans will see a particular post published on their newsfeed.

2) Engaged Users: Engagement is the number of people who clicked anywhere in your post. Engagement is important since it helps you understand if the content you are posting is interesting to your facebook audience.
Again, note that simply looking at the raw engagement statistics is not enough to see what posts are most engaging. The best way to analyse engagement is to calculate the engagement % =( engaged users/ reached users ) * 100

3) Talking about this: People “talking about this” are story tellers i.e. they create stories out of your posts. What are stories? Well, simple. If someone likes, shares or comments they are generating stories through your post.

4) Click through rate: This measures the number of people who have clicked on your post to view a larger version of your photo, a link on your content or watched a video. The CTR really measures how many people are interested enough to pay attention to your content.

5) Negative Feedback: This aims to measure any negative action a user takes for instance – hiding a specific post, hiding all future posts, unliking the page or even reporting it as spam.