Unlike “3G” and “4G” in the mobile phone space which refers to “third generation” and “fourth generation” technologies, the “2.4G” and “5G” designators in WiFi radio frequency bands are shorthand for the 2.4GHz band, and 5G 5GHz band (roughly 5.1 to 5.8 GHz, with some gaps in between depending on the country and regulator agency).
There’s a sound article on the Linksys website that highlights these differences linked below.
In the United States, the FCC set aside the frequencies 2,400-2,483.5 MHz and 5,150-5,725 MHz for unlicensed broadcasts such as Wi-Fi, cordless phones, etc.
The upper frequency of a band minus the lower frequency of a band is the “bandwidth”. The bandwidth of a frequency band is directly proportional to the rate at which data can be transmitted. The bandwidth of the 2.4 GHz band is about 80 MHz and the bandwidth of the 5 GHz band is about 570 MHz. Therefore Wi-Fi can transmit data faster on the 5 GHz band because it is wider.
* The ranges given here aren’t 100% accurate. The way the FCC splits up the electromagnetic spectrum is too complicated for any layman understand. (that’s me for sure)
Microwaves are a huge source of interference for Wi-Fi. Microwaves heat up food by showering it with 2.4 GHz radiation. Some of this radiation leaks out and confuses Wi-Fi receivers when the microwave is running. Cordless phones also often operate on the 2.4 GHz band. The 5 GHz band is used by fewer devices, so the amount of interference on it is less.
The radio engineer formula gives the path loss in dB:
L = 20 log10 (4ℼd f ∕ ƛ)
where L is the path loss in decibels, d is the distance traveled by the signal, f (added) is the frequency of the signal, and c is the speed of light. Based on this equation, we can expect the path loss to be 20*log10(5/2.4) = 6.3752 dB more for a 5.0 GHz signal than a 2.4 GHz.
Transmit a pair of signals at 2.4 GHz and 5.0 GHz with 100 mW of transmitting power each. If the 2.4 GHz signal received is 10 mW, then the 5 GHz signal will only be 2.304 mW at the same receiver.
TLDR: 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.
The higher the frequency of a Wifi signal, the shorter it’s range. The biggest reason for this is that higher frequency signals cannot penetrate solid objects like walls and floors as well as lower frequency signals. (think bass vs treble) Thus, the 2.4 GHz has a farther range than the 5 GHz frequency.