Is all wireless connection today fundamentally done by light?

[kenny1999]

Only differed by frequency, wavelength but they are all fundamentally done by light, is that right?

When you put a physical credit card or stored value card near a payment device provided by the merchant, is it using the identical technology as that when you put your mobile phone close to the device and pay with your mobile phone without physical card?

Edited November 8, 2022 by kenny1999

[Sensei]

WiFi uses 2.4 GHz and 5 GHz (with 20 and 40 MHz channel widths)

NFC/RFID use 13.56 MHz.

https://en.wikipedia.org/wiki/Near-field_communication

https://en.wikipedia.org/wiki/Radio-frequency_identification

(I suggest reading Wikipedia)

 

Edited November 12, 2022 by Sensei

[swansont]

Most is electromagnetic, but some wireless technology uses sound waves.