The validator helps to validate your structured data on your website for general purposes.
This is what Schema.org said according to the announcement:
“As agreed last year, Schema.org is the new home for the structured data validator previously known as the Structured Data Testing Tool (SDTT). It is now simpler to use, and available for testing. Schema.org will integrate feedback into its draft documentation and add it more explicitly to the Schema.org website for the next official release.
SDTT is a tool from Google which began life as the Rich Snippets Testing Tool back in 2010. Last year Google announced plans to migrate from SDTT to successor tooling, the Rich Results Test, alongside plans to “deprecate the Structured Data Testing Tool”. The newer Google tooling is focused on helping publishers who are targeting specific schema.org-powered search features offered by Google, and for these purposes is a huge improvement as it contextualizes many warnings and errors to a specific target application.”
So what’s the difference between Google and Schema.org?
With Google’s rich results testing tool, it will show users strictly supported structured data schema by Google. But with Schema.org’s validator, it’s meant to help you debug structured data types outside of Google’s structured data schema.