802.11a is a Wi-Fi standard developed by the IEEE for transmitting data over a wireless network. It uses a 5 GHz band and allows data to be transferred up to 54 Mbps. Other standards within the 802.11 family include 802.11b, which transfers data up to 11 Mbps and uses a 2.4 GHz band, and 802.11g, which also uses a 2.4 GHz band, but can transfer data up to 54 Mbps.
802.11b is a Wi-Fi standard developed by the IEEE for transmitting data over a wireless network. It operates on a 2.4 GHz band and allows for wireless data transfers up to 11 Mbps. A faster standard, called 802.11g, was introduced a few years after 802.11b and supports data transfer rates up to 54 Mbps. This can make a difference in the speed of data transfers within a local network, but since broadband Internet access is limited to around 5 Mbps, a 802.11b wireless connection will not be a bottleneck for Internet access. Most wireless networks are based on either 802.11b or 802.11g.
802.11g is a Wi-Fi standard developed by the IEEE for transmitting data over a wireless network. It operates on a 2.4 GHz bandwidth and supports data transfer rates up to 54 Mbps. 802.11g is backward compatible with 802.11b hardware, but if there are any 802.11b-based computers on the network, the entire network will have to run at 11 Mbps (the max speed that 802.11b supports). However, you can configure your 802.11g wireless router to only accept 802.11g devices, which will ensure your network runs at its top speed.
802.11n is a wireless (Wi-Fi) standard that was introduced in 2007. It supports a longer range and higher wireless transfer rates than the previous standard, 802.11g.
802.11n devices support MIMO (multiple in, multiple out) data transfers, which can transmit multiple streams of data at once. This technology effectively doubles the range of a wireless device. Therefore, a wireless router that uses 802.11n may have twice the radius of coverage as an 802.11g router. This means a single 802.11n router may cover an entire household, whereas an 802.11g router might require additional routers to bridge the signal.
The previous 802.11g standard supported transfer rates of up to 54 Mbps. Devices that use 802.11n can transfer data over 100 Mbps. With an optimized configuration, the 802.11n standard can theoretically support transfer rates of up to 500 Mbps. That is five times faster than a standard 100Base-T wired Ethernet network.
So if your residence is not wired with an Ethernet network, it's not a big deal. Wireless technology can finally keep pace with the wired network. Of course, with the faster speeds and larger range that 802.11n provides, it is more important than ever to password protect your wireless network.