An impression is one showing of a post on someone’s screen. The same person scrolling past a post twice gives two impressions. For years networks reported impressions; Meta has since replaced impressions with views on Facebook and Instagram, and other networks call the same idea views, plays or displays.
Views are useful for knowing how much a post was shown, and for video they often mean a play of a few seconds or more. On their own they say little about interest: a post can be shown a lot and ignored. Read views with reach (how many people) and engagement (how many reacted) to know whether a post was seen, and whether it worked.
