The 5 GHz band is a frequency range used by compatible Wi-Fi devices and access points. It can offer useful capacity and different interference conditions from 2.4 GHz, but obstacles, distance, channel rules and equipment support still matter. A 5 GHz Wi-Fi connection is separate from the 5G name used for a cellular network generation.
A practical example
A streaming box near an access point may perform better on a suitable 5 GHz connection than on a congested 2.4 GHz connection. Moving it farther away or behind obstacles can change that comparison because the local radio path also changes.
A common misunderstanding
Do not confuse 5 GHz Wi-Fi with 5G mobile service. They name different technologies, and selecting one on a router does not turn a household connection into cellular internet.
Related terms
Stable technical definition. Editorial approach