It’s confusing, isn’t it? They are mostly political terms, so the exact definitions are probably non-existent, but let’s settle for vague. I do think they’re different and important to distinguish, so here’s my stab at explaining what the differences are between bio-, green and the circular economy, and then I throw in water sensitive design as a bonus. Oh, and distributed. That’s what all of these have in common. This is just my opinion, of course.