Which track on an access card’s magnetic stripe is read-only and includes card number information?

The first track on a magnetic stripe, known as Track 1, is indeed a read-only track that contains card number information. This track typically stores alphanumeric data, which allows it to encode not only the cardholder's account number but also additional features such as the cardholder's name, expiration date, and other relevant information.

It is important to note that this track is formatted according to specific standards, which enable compatibility with a wide range of card readers. Being a read-only track, the information here cannot be altered or overwritten during a transaction, ensuring the integrity of the card number and associated data. The read-only nature of Track 1 adds a level of security, as it prevents unauthorized changes to sensitive information.

In contrast, the other tracks on the magnetic stripe serve different purposes and may be writable, which allows for more flexibility but can also introduce risks associated with data alterations. Therefore, the characteristics of Track 1 make it uniquely suited for securely holding the primary account information in a standardized format that card readers can easily interpret.