There are many kinds of documents used to prove one’s identity: ID card, polling card, citizenship card, passport, visa, residence permit, driver’s license, as well as a professional licenses such as a flight crew card.
Generally speaking, this is a document issued by a trusted authority (usually a government, although it may delegate this task, or a recognized international organization) that will contain the bearer’s identity (first and last names, birthdate, possible affiliation, address, etc.) as well as some biometric information (photo, fingerprints) that can link this identity to the individual.
An identity document is issued at the end of a carefully developed and controlled enrollment process that aims to ensure the document is created in the name of the right person and delivered to the right person. This process has, of course, been attacked by forgers who try to have identity documents wrongfully issued to themselves containing their biometric characteristics linked to a made-up identity, or worse yet, to the identity of an existing person (see Identity theft).
Additionally, ID documents used vary from one country to the next; having one ID document (passport or ID card) is required in some countries and not in others. Other nations have no identity cards at all. The situation varies greatly in Europe alone.
The most common document types are: