Please Explain the what do you mean by private Exchange and public exchange ?

In the public exchange, you can access hundreds of templates

examples, and connectors made available to you by MuleSoft.

In the private exchange, you can expose your own internal assets so that your organization can get the most benefit from each asset or project that you create.

Please go through the links to get better idea :-

Ref :- http://blogs.mulesoft.com/dev/anypoint-platform-dev/demo-anypoint-exchange/