Answer:
B, G and N are standards of how wireless devices work; the speed data is sent and the strength of the signal (how far will the signal go) are the two items that concern most people. The frequency and other items are part of the standards also. Actually B and G are the only standards, N is still being approved, should be approved in December 2009. IEEE makes all of these standards (or rules). B, G and N are all part of the 802.11 standard.

B is the original mass used wireless standard. Since it is a standard all the manufacturers who say the equipment is B standard will work with all other equipment that is B standard. Originally it was called WiFI, although today B, G and N are now all called WiFi. B works at 11 megabits per second (mbps). The maximum distance between devices is 100 feet although you may not get a signal that far depending on objects in the way. B devices can only receive and send a B signals.

G devices have been around several years and work at 54mbps. They can go a little further than 100 feet but would need a clear path to do that. G devices will see whither the other device is B or G and then communicate with the device at the speed of the slower device. You can set your G device to only communicate with G devices or with both B and G. They are 5 times as fast as B. A lot of wireless networks today use G.

N devices work at 100-120mbps and I expect the final speed to be in that range in the standard. They can talk at a distance of 300 feet (some studies claim with clear line of sight it can be much longer) but the speed will drop drastically toward 300 feet.

You will find devices that will be N called N , super-boosted, boosted and other terms. Since it is not a standard yet manufacturers have made their devices to work the best under their idea of what the standard will be. Equipment from different manufacturers that are N may not work at their highest speed due to this and work like G. N devices work with B and G like G does with B. The N device determines the slowest and runs at that speed assuming you chose to use B, G and N on the device. Once the standard is approved in December I expect there will be firmware updates available form the manufacturers for all their N devices to make them standard compliant. If you registered the device I expect you will get e-mails within a day or two telling you a free update is available and give directions. When dialup modems 56K speed was standardized that is what happened. If you choose to use N now get all your equipment from the same manufacturer to assure you get the benefits of N. Some equipment from different manufactures may work at N speed, but that is iffy.

If you are buying new wireless devices today you want to get either G or N. Normally N costs more, but the prices are getting rather close.

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