Wireless access to the internet has become the norm these days for personal use. There are plenty of choices depending on what you need, from cable modem & wifi router combinations, to straight wireless access points that connect to your existing gear.
A wireless mesh is a design that allows a single access point to connect to an existing internet connection, with the other access points only requiring a power connection. Once online, the other access points use a different form of wireless to securely connect to the main AP and use its connection to the internet to broadcast the signal over a wider area , thus creating a “mesh” of wireless signal throughout the installation area (ex. multiple rooms in your house).
There are several options available, so look for the best price and options that work for you. I purchased an Eero 2-pack, and have been really happy with the speed it gets.