By John R. Delaney for PC Magazine:
When choosing a new router, you should consider the size of your coverage area and the number of clients, as well as the types of devices that will connect to the router.
Not all routers are created equal. Some models can only communicate over a single radio band, while others can use two. Single-band routers operate on the 2.4GHz frequency band and are typically the least expensive models out there, but they have to compete with other devices in the home that are on the same radio band, such as microwave ovens, Bluetooth devices, and wireless phones. That said, they are perfectly adequate for things like Web surfing and connecting to social media services like Facebook and Twitter.
If one or more of your devices will be streaming video from a service such as Netflix, or connecting to an online gaming service such as Xbox Live, consider a dual-band router. These have two radios; one connects to the 2.4GHz band, and the other connects to the 5GHz band. The 5GHz band is typically less crowded than the 2.4GHz band and offers more throughput, with minimal signal interference, making it ideal for video streaming and gaming duty. Dual-band routers allow you to assign a band to specific applications and clients, thereby easing the load on both bands.
Then there are tri-band routers. These have three radios—one that operates at 2.4GHz and two that operate at 5GHz. These models are a good fit for multi-device households that experience heavy network traffic. lots of video streaming, torrent downloading, file transfers, and online gaming.