2. How NFC technology works?

NFC, or Near Field Communication, is a handy technology that lets devices share information wirelessly when they're close together.

The Key Players:

• NFC chip: This tiny antenna and chip combo lives inside both smartphones and NFC tags. It's like a miniature radio station.
• Electromagnetic field: When an NFC-enabled device is turned on, its chip generates a weak electromagnetic field around it.
• Data exchange: When an NFC tag enters this field, the chip in the tag gets energized and transmits information back to the device. This information can be anything from URLs to payment details.

NFC operates in a specific range of the radio spectrum, unlicensed for industrial, scientific, and medical (ISM) purposes. This range is further divided into three sub-bands:

• Low-frequency (LF): 135.6 kHz This band offers the shortest range (up to about 4 inches) but provides the highest power output, making it suitable for applications like contactless payments and ticketing.
• High-frequency (HF): 13.56 MHz This band offers a good balance between range (up to about 20 inches) and power consumption, making it suitable for a wider range of applications, including data exchange, peer-to-peer communication, and access control.
• Ultra-high-frequency (UHF): 433 MHz This band offers the longest range (up to several feet) but has a lower power output compared to LF and HF. It's mainly used for specialized applications like asset tracking and industrial automation.

We can summarize its features as follows:

• Short range: NFC works best within a few inches, making it secure and less prone to interference.
• Passive tags: Most NFC tags are passive, meaning they don't have batteries. They simply draw power from the electromagnetic field generated by the reading device.
• Active and passive modes: NFC devices can act as both readers and tags. Your phone can read information from passive tags and also share its own data with other NFC devices.

Basically, he information is shared between devices in three steps:

• Initiation: For example, a cellphone passes over an NFC tag on a poster. The phone's NFC chip detects the tag's field and powers it up.
• Communication: The tag broadcasts its data (e.g. website address or payment info) back to the phone's chip.
• Interpretation: The phone's software decodes the received data and figures out what to do with it. It might open a website, initiate a payment, or display stored information on the screen.