A card reader is a device that reads data from a magnetic stripe on a plastic credit or debit card. A key fob, on the other hand, is a small transmitter that is often used to unlock car doors or start cars.
Typically, a key fob will include an electronic chip that stores a unique identifier number. When you push a button on the key fob, this number is transmitted wirelessly to the car, which then verifies it against its database of authorized users and unlocks the door or starts the engine. Card readers don’t typically include this type of security feature.

The most common reason is that the biometric sensor is not able to accurately capture a person’s biometric data. This can happen if the sensor is dirty or dusty, if the person being scanned is wearing gloves, or if the person’s hands are excessively dry or oily.
Another common reason for authentication failures is that the biometric data captured by the sensor does not match the corresponding data stored in the system’s database. This can happen if the reference image in the database is of poor quality, or if there has been some kind of change in the appearance of the person since they were initially enrolled. Be sure to keep your employee data updated and your system well maintained.