Database theory

Database theory is like a big file cabinet. Every file in the cabinet holds information about something, like where a person lives, what classes they took in school, or which movies they like to watch. All of the information is organized in a way that makes it easy to find things, just like a real filing cabinet. The theory behind databases is how to organize all of that information so that it can be easily found. For example, if you have a database of movies, you might arrange it so that you can find a movie by its title, its rating, or its year of release. That way, if you wanted to find a good movie that was released in 2020, you could just look up 2020 in the database and it would show you a list of titles that fit that criteria.