Single-band routers use a 2.4 GHz band and are limited in range and speed compared to dual-band routers, which use both the 2.4 GHz and 5 GHz band. Dual-band routers are more efficient, have longer range, are less prone to interference from household devices, such as microwaves and older cordless phones, and are faster. However, this efficiency is maximized when using 5 GHz compatible devices. When 5 GHz devices are not within range, only the 2.4 GHz band gets used. Dual-band routers are also more costly than single-band routers.
Wireless routers are either single-band or dual-band. Single-band routers use the 2.4 GHz band and are limited to one wireless signal. Dual-band routers use two bands -- 2.4 and 5 GHz -- which means that they are broadcasting two simultaneous wireless signals, providing better performance.
Single-band routers use 2.4 GHz only and are limited in speed to the Internet connection and speed of the router itself. Dual-band band routers support both 2.4 GHz and 5 GHz bands and provide faster speeds.
Dual-band routers have longer range and better signal strength, and despite their broadcasting on two different bands, there is no need to switch between bands manually, as they switch automatically when needed. Single-band routers have shorter range and their signal strength is not as strong.
Single-band routers are compatible with most wireless cards and receivers, as they broadcast on the 2.4 GHz band, which is common. Dual-band routers that use both 2.5 and 5 GHz may experience wireless connection to 2.5 GHz compatible devices, and 5 GHz compatible devices simultaneously. However, if no 5 GHz compatible device is in range, only the 2.5 GHz band gets used.
Dual-band routers are significantly more expensive than single-band routers, sometimes two to three times the price of a single-band router, as of February 2012, according to PCMag.com.