What is the difference between 2.4G and 5G wireless?

Unlike "3G" and "4G" in the mobile phone world which refer to "third generation" and "fourth generation" mobile phone technology, the "2.4G" and "5G" numbers in Wi-Fi are radio frequency bands. 2.4G is short for the 2.4GHz band, and 5G is short for the 5GHz band (roughly 5.1 to 5.8 GHz, with some gaps in between depending on the country and regulator agency).

There is a reasonable article on the Cisco website Linksys website that highlights the differences.

In a nutshell, the 2.4GHz band gives you longer range, whereas the 5GHz band offers more channels that are less likely to be polluted with interference.

It is better to use the 2.4 GHz wireless band if you are going to connect over a larger distance (but unlike 5ghz, it's more likely to have network traffic). The 5 GHz band offers higher bandwidth for faster downloading, uploading and streaming videos online, but works best over shorter distances without many obstructions such as walls,

802.11b - 11 Mbps (2.4GHz)
802.11a - 54 Mbps (5 GHz)
802.11g - 54 Mbps (2.4GHz)
802.11n - 600 Mbps (2.4GHz and 5 GHz) - 150Mbps typical for network adapters, 300Mbps, 450Mbps, and 600Mbps speeds when bonding channels with some routers
802.11ac - 1300+Mbps (5 GHz) - newer standard that uses wider channels, QAM and spatial streams for higher throughput

Actual wireless speeds vary significantly from the above theoretical maximum speeds due to: distance - distance from the access point, as well as any physical obstructions, such as walls, signal-blocking or reflecting materials affect signal propagation and reduce speed interference - other wireless networks and devices in the same frequency in the same area affect performance shared bandwidth - available bandwidth is shared between all users on the same wireless network.