My questions:

1)What is Bsnl`s EVDO,WiFI,WiMax?

2)What are the uses, advantage, disadvantage in using these 3 and which is best on what occasions?

3)I heard my friend saying that u can use WiMax if u want one connection to use between home and office?
If my office is 100km(say) away from my home can i still use WiMax?