[FTA]

You just hold the card over the screen and it reads (I believe) an RFID chip in the card. No swiping or card insertion required.

[gokhan]

And it's much faster most of the time.

[ryandrake]

How do you know if your card supports it? Try it and see if it works?

[FTA]

I had no clue until a cashier did it for me in a European country. There may be a little logo like this either on your card or on the materials when you get your card: https://en.wikipedia.org/wiki/Contactless_smart_card#/media/....

Once it was demonstrated to me, I went back and found out the cards I've had since 2013 (pre-chip).