Have you ever helped your friend with something like sharing your toys or doing a puzzle together? That's kind of like what marketing co-operation is! It's when two different companies or brands work together to help each other out and achieve their goals.
Let's say your favorite toy store and your favorite candy store want to work together. They might make a plan to put some candy in the toy store or put some toys in the candy store, so that the customers of one store might find out about the other store and go there too! That's called cross-promotion.
Or, they might make a special deal where if you buy a certain toy, you get a coupon for candy, or if you buy a certain candy, you get a discount on a toy. That way, both stores are helping each other get more customers and make more sales! That's called co-marketing.
So that's what marketing co-operation is all about. It's like teamwork between two different companies to help each other out and make both of them more successful!