The Instagram algorithm! It's a complex system that determines what content to display in your feed. Here's a simplified breakdown: Instagram uses a combination of factors to rank posts, including engagement, relevance, timeliness, and relationship between you and the user posting. Posts with high engagement (likes, comments, saves) are considered more relevant. The algorithm also takes into account your past behavior, such as which accounts you interact with and what content you engage with. Additionally, it looks at your device and location to personalize your feed. This helps ensure you see content that's most likely to interest you.