what is the diffrance between wireless N & G usb network adapter?
Network Adapters Wireless N format support wireless N network, which has theoretical maximum data stream up to 150 Mbps (with 4 independent streams) and also support MIMO.
N wireless adapters work in environments Wireless N and Wireless-G
Wireles G adapters are just your bog standard 2.4 ghz B / G adapter supports formats B and G network. They can connect to wireless N networks, but they can not transmit and receive at their normal speed 54mbps, and thereby also limit the speed WLAN Router 54mbps across the board.