The “Catering to Cats and Dogs” Forums are like social mixers where everyone is at an equal level, milling about and discussing with other. These many to many descusions allow anyone to start a topic and anyone to respond to anyone. Members are often at equal level, and content is usually segmented by topic. (rather than by people).

The “Catering to Cats and Dogs” Blogs are like a keynote speeches where the speaker (the Blogger) is in control of the discussion, but allows questions and comments from the audience.
The Blogs are journals often authored by one individual.