ELI5: Explain Like I'm 5

Filter (mathematics)

Okay, imagine you have a big pile of toys that you want to sort. Let's say you only want to keep the red ones. You don't want to throw away the other toys, you just want to separate them for now.

That's what a filter does in mathematics! Instead of toys, it works with numbers, and it separates them into categories. For example, let's say you have a list of numbers like this: 2, 5, 8, 3, 6, 1, 10, 9.

Now you decide you only want to keep the numbers that are bigger than or equal to 5. So you use a filter, and it separates the list into two categories: the numbers that meet your condition (5, 8, 6, 10, 9), and the ones that don't (2, 3, 1).

Basically, a filter is like a magic tool that helps you sort things based on some criteria that you decide. It does all the work for you, so you can focus on what's important. Whether you're sorting toys, numbers, or anything else, a filter is a great way to make things more organized and manageable!