Final answer:
An apostille is an official certification for verifying the authenticity of a document for international use, established under the Hague Convention of 1961. It involves a unique seal from a competent authority to ensure that a document is recognized as valid in another signatory country.
Step-by-step explanation:
An apostille (or authentication) is an official certification that is used to verify the authenticity of a document for use in another country. This process is essential in international legal matters, where a document from one country needs to be officially recognized in another. The apostille ensures that public documents issued in one signatory country will be recognized as valid in another signatory country without further authentication.
The concept of the apostille was established under the Hague Convention Abolishing the Requirement of Legalisation for Foreign Public Documents in 1961. When a document is apostilled, it receives a unique seal from the competent authority in the country where it was issued, such as the Secretary of State or Foreign Affairs department. This sealed and signed certificate is then attached to the original document, indicating that it has been officially authenticated.