A major difference between 802.11 a/b/g and 802.11 n is the difference of speed. The speed of 802.11 a/b/g is 5 GHz/ 2.4 GHz/ 2.4 GHz. on the other hand speed of 802.11 n is 2.4/5 GHz.

Another difference lies in range. Range of 802.11 a/b/g is 50/150/50 feet and the range of 802.11 n is 175 feet.

There is a huge difference in speed of these standards. The speed of 802.11 a/b/g is 54/11/54 Mbps and speed of 802.11 n is 300 Mbps to 400 Mbps.