If you don't work for a company that supports this, then this feature is pretty much useless, and can be safely ignored. You need to be in possession of that physical 'key' (RSA tag) as well as know your username / password to log in. Before you can use a Smartcard, you must install a Smartcard reader on your host computer. The concept is the same as those RSA keychain tags people carry, that automatically generate a new code every 60 seconds. You need both the password AND physical smartcard to log in. This way, you protect against single-factor authentication attacks such as password-based attacks (keylogger, weak passwords, leaked passwords) and you protect against stolen keys / smartcards.

The idea is that you plug in the smartcard to the laptop, and also type in a username / password, in order to log in. You'll usually find this in larger companies with mature IT infrastructure. You'll only find smartcard readers on enterprise-grade laptops, since they don't have a use in the consumer space. You can customize some of their business line models with a Smart Card reader. Omnikey-based smartcard keyboard - NHS compatible. The Cherry 6644 smartboard is a quality UK layout keyboard with built-in Omnikey-compatible reader supporting secure PIN entry.

For computers with no built-in smart card reader, external smart card readers attach via Universal Serial Bus (USB) or serial port to provide smart card access to the computer. Smartcard slots are for companies that support two-factor authentication for logins. A lightweight NHS smartcard reader with standard USB CCID interface. Computer smart card readers are included on most computers that come equipped with smart card security technology.

Computer with smart card reader