Bean Validation, or JavaBeans Validation, is a model for validating data in Java objects. The model uses built-in and custom annotation constraints to ensure the integrity of application data. The specification is documented here: http://jcp.org/en/jsr/detail?id=303.
Hibernate Validator is the JBoss EAP 6 implementation of Bean Validation. It is also the reference implementation of the JSR.
JBoss EAP 6 is 100% compliant with JSR 303 - Bean Validation. Hibernate Validator also provides additional features to the specification.