The magnetic stripe consists of a series of zones, where the field points up or down, corresponding to 1 or 0:
RFID tags use radio-waves, which can be sensed from a distance. The trouble is, producing radio-waves requires power, and it would be inconvenient to attach a battery to every card. That's where RFID tags get clever:
|From Priority 1 Design|
When I was growing up, and dreaming of being a scientist, one of my planned inventions (aside from my mother's "Beam me up" technology) was wireless power. It seems I'm about 70 years late for that, but there's plenty more to discover!