802.11n is a wireless networking standard published in 2009 that was created to offer higher speeds and greater ranges than its predecessors. It offers data rates of up to 600Mbps, which allow for faster downloads and uploads.
The 802.11n protocol operates on both the frequency bands at either end of the spectrum (i.e., through radio waves with wavelengths between about 15 cm and one meter). 802.11n transmitters and receivers use a wider channel, which improves performance by reducing the effect of interference from other devices operating on nearby frequencies at close distances to each other. It is capable of transmitting data over multiple antennas so it can more efficiently route traffic in different directions instead of broadcasting transmissions out in all directions like 802.11b/g does (called spatial diversity).
The 11N protocol offers the option for MIMO or multi input multi output: this allows transmission between two points that are not line of sight, such as through walls and floors, even if they do not have an unobstructed path to one another. It also utilizes beamforming technology to steer radio waves towards destination devices rather than broadcasting them out in all directions.
Devices that use 802.11n, such as a wireless router, can transfer data at more than 100Mbps. The 802.11n standard theoretically supports data transfer rates of up to 500 Mbps when configured optimally with a good antenna and line of sight. 802.11n operates five times faster than 100Base-T Ethernet networking.
If you do not have an Ethernet network, it does not matter that much. Maintaining the quality of your Wi-Fi network has been a challenge, but 802.11n fixes this problem.