What is defined as a "boarding pass"?

A boarding pass is specifically defined as a document provided by an airline during the check-in process. It serves a crucial function by granting the passenger permission to enter the restricted areas of the airport, such as the boarding gates, and also allows them to board the airplane itself. This document contains essential information, including the passenger's name, flight number, departure time, and boarding gate, which are all vital for a smooth travel experience.

The correct answer captures the dual role of the boarding pass: it is not just a simple ticket or an entry document, but a formal authorization enabling the passenger to navigate through airport security and access their flight. Other options describe concepts related to air travel, but do not accurately reflect the purpose and nature of a boarding pass. For instance, a document allowing entry to the airport premises refers more to airport access documentation rather than the boarding process itself.