Difference between validating and non validating parser
Oxygen validates your schema against all of the processors in one action.
When creating XML documents, errors can be introduced.
Working with large projects or a vast number of files increases the probability that errors will occur.
Identifying and resolving errors in your project can be time consuming and frustrating.
Suppose that you are working with a large XML document that you decide to split into multiple files and use external entities to merge those files into a master document.
If you edit one of those files then you would want to check that the master document is valid.