Here is a good and down-to-earth explanation: https://www.stephanboyer.com/post/132/what-are-covariance-and-contravariance https://www.stephanboyer.com/post/132

Here is a good and down-to-earth explanation: https://www.stephanboyer.com/post/132/what-are-covariance-and-contravariance https://www.stephanboyer.com/post/132/what-are-covariance-an...