TikTok, YouTube, Google, and Netflix all rely on algorithms to filter content. They take information like your location, your viewing and/or browsing history, things you've liked or engaged with before, and try to show you more of what all of that information (given certain weights and values) says you should like. This is accomplished through algorithms!
Algorithmic Literacy is understanding the processes that determine what you see online and that you have a role in shaping the digital world you encounter. Algorithmic literacy enables you to think critically about what you're shown and understand that it might not be the best or most truthful information, that it's subject to biases which attempt to replicate your own biases. In short, the algorithms are not showing you the best or the truth; they're only trying to give you what they determine you want.
Play around with these programs to see how AI and algorithms respond to your input: