Glossary
What is NODATA?
The domain exists, but no record of the queried type was found.
A DNS name can exist without having the record type you requested. A query can then return an empty record list without an error response code; this situation is called NODATA. Query the same name separately using types relevant to your task, such as A, AAAA or MX.
Example
An example domain can have an A record but no AAAA record. An empty AAAA answer does not mean its A record is also missing.
Common issue
NODATA does not mean the name is absent or that the whole site is offline. A query that receives no response is also different from a successful query returning an empty answer.