Intuitively, entropy is the measure of in how many states a system can be. But how can we arrive from this intuition at \( H(X)= -\sum_i p_i \log p_i \)?
...a monoid in the category of endofunctors. This enigmatic sentence keeps perplexing beginner programmers. In this post we dissect it so you don't have to read a whole book on category theory in order to understand what it means.