Further reading
Most companies give a radio-frequency identification (RFID)-based ID card to their employees so that it becomes easy to track their attendance as well as ensure entry of only authorized people into the office. You can find out more about how RFID works at https://lowrysolutions.com/blog/how-rfid-and-rfid-readers-actually-work/.
Ready-made RFID tags are available on the market. You can interface them with an Arduino programming board and build your own RFID-enabled items in the future.
