* Creating the product right.
* Usually done at component, integration, and system testing by developers and/or testers.
* Creating the right product.
* Usually done at acceptance testing by the stakeholders/customers.
A very good book in software testing by Rex Black: “Foundations of Software Testing ISTQB Certification”
I suggest testers (or those who want to get into software testing) know more about ISTQB certification (and the organization itself) and make it as one of your goals [istqb.org].
This post does not in anyway represent the views of my employer and was written with the objective of knowledge-sharing and does not intend any infringement of existing intellectual properties.