Readers are usually connected to another system. Let’s use an access control system as an example. The carrier would be a company employee. This person would have an access control card as a RFID tag. The reader would be a smartcard reader that is mullion mounted next to secured doors. The reader would be connected to an access control system.
In the access control system access rights for people are stored and people are linked to a number. This number is also stored on the RFID card. If the access control system gets information from the reader, it will look in its database to check if this person has access rights. If so, the system would be sending a signal to a door that it can be opened.
RFID is for example used to identify clients by healthcare agencies, animals in livestock management systems, students that use lockers to store belongings and taxis that request access to passenger pick-up areas at airports.
There are many variations to this setup. A wide variety of RFID systems have been implemented in the world. Livestock management systems deal with identification of cattle to automate feeding and milking or optimize heat detection. Vehicle access control systems use RFID in buses, taxis and ambulances to allow to them secure and convenient access to bus depots, taxi stands or first help entrances. Retail stores use RFID for securing goods and inventory checking. Logistics departments use RFID to track parcels in warehouses and during transport. Libraries use RFID to identify books and members in elf service applications. Billions of RFID tags are used in our world on a daily basis in millions of applications.