The wireless network operates on a spectrum of channels. Wireless devices operate on either the 2.4 GHz band or the 5 GHz band of this spectrum.
The 2.4 GHz band has 11 channels to utilize, while the 5 GHz band has 20 channels to use.
Competition for these spectrum channels is known as interference.
Traffic on the 2.4 GHz Highway
Household devices, including everything from baby monitors to microwaves, run on the 2.4 GHz band and all fight for space on the 11 channels of this band. Networks (aka SSIDs) are literally waiting for the airwaves to be clear enough to send information to your router and back to the device you are operating. Needless to say this band tends to get crowded, especially at peak use.
Depending on the age and capabilities of a device, the 2.4 GHz band may be your only use option.
Traffic on the 5 GHz Highway
Newer devices operate on the 5 GHz band. At the same time, this has almost double the channels, so there is much less interference. To top that, the GHz band travels much faster, enabling high-speed internet connections.
The primary differences between the 2.4 GHz and 5GHz wireless frequencies are range and bandwidth. 5 GHz provides faster data rates at a shorter distance. 2.4 GHz offers coverage for farther distances but may perform at slower speeds. Range: how far your data can travel.