Title, authors and editors, publication, publication and deposit dates, type, publisher, pages, ISSN/ISBN, abstract, license and the final destination URL of the DOI.
Check that you typed the full DOI correctly (e.g. 10.12345/abc123). DOIs registered with other agencies (DataCite, mEDRA) do not appear in the Crossref database.
It is the address the DOI currently resolves to. The tool follows the doi.org redirects and shows the final page — useful to confirm the DOI points to the right place.