With a traditional Wi-Fi system, just one device – the router – would be responsible for producing a Wi-Fi signal. However, in a mesh Wi-Fi system, several devices would do this job – not just a main router, but also a series of nodes placed around the property.
All of these devicesform the same wireless network; for example, they all share the same SSID and password. These devices also wirelessly communicate with each other to ensure that, wherever you are in the property, your Wi-Fi signal is coming from the nearest of those access points.