Attestation (also called legalisation) is the chain of official endorsements that proves a foreign document, such as a degree, marriage certificate, or birth certificate, is genuine so it can be used in a GCC country. The typical path runs through the issuing country's relevant authority, then its Ministry of Foreign Affairs, then the destination GCC country's embassy, and finally that country's Ministry of Foreign Affairs.
Attested documents are needed for many residence and family transactions, including sponsoring a spouse or child, certain professional licences, and equivalency of qualifications. The exact steps depend on which country issued the document and whether that country is part of the Apostille Convention, which can shorten the process.
Because requirements vary by document type and country pair, and some GCC states now accept digital MOFA attestation, the current path should be confirmed for the specific document before starting.