Help: understanding scanning cards data through the air

[shlomiYo]

Hey Guys,
It would be amazing if anyone has any idea of how does'e it happens?
I have heard in my company that the manager installed a new system to read my employee card in my packet from the ceiling, and i wanna know how?
What does'e this device do that it can read something so far away through the air? how he does'e that?

Thanks for reading.

 

[MikeMl]

Google "RFID"

 

[dr pepper]

Welcome.
Generally the larger the coil the further away it will work.
I'd better not say anymore for security reasons.

 

[shlomiYo]

Thanks for your replays guys, this is for an educational purpose only.
What is so special in this RFID tag that make it readable with this device?
What stops people of walking near me with this device and a small power source and steal my credit card ?
Thank you

 

[ronsimpson]

Here is a picture of what is inside some RFID cards. The "coils" of wire is an antenna. At close range the card gets enough power from the antenna to power up electronics, which signals back its ID.