The equipment with the "n" designation can transmit data at twice the speed of "g" routers and is more than five times as fast as "b" wireless routers.
The difference between an N and a G router is all in what the purpose of your router is for. You need to see if you are using it for a personal or business use.
one is better
Speed and technology (N is a newer, faster technology.)
The same as with wireless G card and G router.
Yes, however, your internet speed will only be that of the G router which is comparably slower than that of an N router.
They are two different protocols. Most (probably all) N routers and networks cards can also do G and probably B protocol. Anything labeled as G will only do G and in amlost all cases B. N is faster than G (but you'd never notice the speed difference if you are just connecting to the internet, they are both way faster than a home internet connection. N should, technically, have a bit longer range than G, but in real-life most people don't see a great deal of difference here.
No.
You can't and you don't want to. A "N" router will work with "G" network components and will additionally support "N" hardware at a higher speed. Converting it to "G" would be a step down.
N is better. It is faster.
Usually they are, you have configure the router for G wireless networks.
In the wireless properties choose "compatibility mode for G" or something like that. If you do so your router will allow both types of wireless cards G and N.
You can use router of G or N type and the same type wireless adapter. Of course you can use wireless N adapter with G-type router and reverse.