Difference between Continuous Integration, Continuous Delivery, Continuous Deployment

An explanation from the book Continuous Delivery with Visual Studio ALM 2015:

Continuous Integration is all about quick feedback and validation of the commit phase.

Continuous Delivery is about establishing a mindset where you can deliver features  at customer demand. 

Continuous Deployment can be viewed as the next level of Continuous Delivery. Where Continuous Delivery provides a process to create frequent releases but not necessarily deploy them, Continuous Deployment means that every change you make automatically gets deployed through the deployment pipeline. When you have established a Continuous Delivery solution, you are ready to move to Continuous Deployment if that’s something your business would benefit from.