What is the comparison between ZigBee and RFID?

It depends on the application.

RFID usually means passive tags, low cost and no battery needed but maximum range only a few inches.

Zigbee ia a PAN network (the nodes all have batteries) range is many yards.

RFID tags generally cost less ($5?) than Zigbee nodes ($25?) but prices vary with quantity.

With RFID to locate something you must scan it from a few inches away. With Zigbee you can detect it from anywhere in the building.

But, Zigbee does not inherently give any location information