The word “Apostille” (pronounced a-pos-TEE, not a-pos-TEAL or a-pos-TILL-ee) is of French origin. It comes from the French verb “apostiller”, which derives from the old French word postille meaning “annotation”, and before it the Latin word postilla, a variation of the word postea, which means “thereafter, afterwards, next”.
An Apostille is specialized certificate of authentication recognized by countries who belong to the Hague Convention Abolishing the Requirement for Legalization of Foreign Public Documents.
It provides a uniform method of validating documents to be used in foreign countries.
It only authenticates the origin of the underlying public document. Apostilles authenticate the seals and signatures of officials on public documents such as birth certificates, notarial certificates, court orders, or any other document issued by a public authority, so that they can be recognized in foreign countries that are parties to the Convention.
If you have been told that you need one, it is because your documents need this type of verification in order to be valid for use in another country.
The Apostille itself is a full page certificate. It is permanently attached to notarized/certified document (removing the staples/clasp is forbidden).