Collaboration is intentional and dedicated work together to achieve some end. Cooperation is a weaker word. It need not be dedicated but there is much overlap between the words.
For example, suppose Sally and Mary are cleaning the dishes together. They cooperate with each other to make the job easier. Sally organizes the things to be cleaned and Mary washes them in the sink. It would sound odd to call that a "collaboration" because the washing of dishes just isn't a sufficiently noteworthy task to merit any dedication.
As another example, suppose Sally and Mary want to change the way that English is taught at their children's school. They want the school to change its policy by switching from American English to British English. It is a controversial idea with much opposition. To make it work, they need to convince many people that their idea is important. So, they meet together to plan a strategy. That is collaboration. They have dedicated themselves to work together to accomplish something.