What are correlated variables?

Correlated variables are two things that move together, like best friends who always know what the other is thinking.

Imagine you have a toy box full of blocks. Every time you take out a red block, you also take out a blue block, they always come in pairs. That's correlation! The number of red blocks and blue blocks are correlated variables because when one goes up, the other usually does too.

Sometimes, like when it’s raining outside, you might take out two red blocks at once, but you still always take out a blue block too. So even though sometimes there are more reds than blues, they’re still correlated because they don’t act randomly.

But if one day you decide to only take out red blocks and forget about the blue ones, then they’re no longer correlated, they're like friends who haven't talked in a while!