Reach refers to the total number of people who have been exposed to a social post or ad. This metric does not necessarily indicate that all of these people have actually seen your content. They could have scrolled right past it, for instance. Reach simply indicates that the content appeared in the user’s social feed at least once.
Social media analytics tools usually report organic reach and paid reach as two separate metrics.
Related: Impressions, Engagement
Learn more: Reach vs. Impressions: What’s the Difference (And What Should You Track)?