What Does Key Fob Mean?
A key fob is a small electronic security device with built-in authentication protocols or mechanisms to allow whoever possesses it to enter a secured network or location in order to access data or services. A key fob is designed to be small so that it can be carried around inconspicuously just like a key chain, hence the name key fob.
Techopedia Explains Key Fob
A key fob usually has a small screen so it can display whatever security code it was meant to contain. It is used as part of a multifactor identification process, which is required for high-security systems. More common security measures are a username and a PIN/password combination, while others only require a certain key or smart card. But two-factor identification requires both, meaning that the person must supply the personal identification credentials plus the associated security device, in this case the key fob.