nodes which can hold different values to be read by a sensor?

Hello guys!

I have a question about sensors which are able to read values of specific "nodes".
The "nodes" in my context are like little metallic materials which can be placed somewhere i.e. within a flat wooden tile and have NO electrical connection.
A sensor should then be able to read values from them.

more detailed example:

I have three "nodes". Each of them is placed on my table. When hovering over the first one with my sensor - the sensor can read a value which can be converted to a digital number value like "1" and the other two "nodes" have different values if read by the sensor - like "2" and "3".

Those nodes should be "progammed" to that value anyhow.

Sorry guys I know this is a weird question - but since so many fantastic things are possible thanks to microcontrollers and electrical components I kinda do not feel that stupid with this questions :smiley:

Thanks for you help !

RFID?