The Facebook algorithm decides which posts you see every time you check your Facebook feed? Also, the order they appear is NOT chronological. The algorithm evaluates every post, scores it, and then arranges it in descending order of interest for each individual user.
The point is to keep people scrolling, so that they see more ads.
What does this mean for your business?
Post frequently at optimal times for your target group and post content that people engage with - the more likes, comments and shares: the better!
If you need help with Online Marketing and Search Engine Optimizatin - give me a shout!