NFC stands for Near Field Communication. As suggested by its name, NFC protocol allows mobile devices and gadgets to communicate with one another and partake in wireless data transfer when they are present in close proximity. This short-range wireless connectivity does not require the help or support of the internet as the process is carried out through simple magnetic field induction.
In order for this to work, both of the devices usually need to be in extremely close proximity, just a few centimeters away from each other, and both of them also need to be NFC enabled in order of the inductive coupling to take place. The short-range requirement of the transaction to occur ensures that the process is relatively secure.
In order to be NFC enabled, your smartphone or device needs to have an NFC chip or tag. These tags essentially store data within them until it is accessed and read by a card reader or an NFC enabled device. These read only tags can store between 96 to up to 8192 bytes of data. They can be used to store credit and debit card information which is useful for contactless payment systems.
Usually, an initiator and a target are involved in the workings of an NFC device. The job of the initiator is to perform the active action by generating a radio frequency that is subsequently used to give power to the target which is passive.
There are two modes in which NFC devices operate. The passive mode is where the initiator provides a carrier field and the target device simply modulates this field to produce a response, much like a transponder. On the other hand, in the active mode, both the initiator and the target device produce their own fields alternatively, turning it off when they are receiving data and responding by producing their own communication signals.