WiFi Boosters with Ethernet Cables: How to Connect Them

Often, yes. Depending on the model, the Ethernet port may provide a wired connection to a device, or the extender may support access point mode from a router connection; check its manual for the supported mode.

Only if the extender supports a wired access point or Ethernet backhaul mode. Follow the manufacturer’s instructions and use the correct port and operating mode.

A cable gives a direct wired path where you can run one. A wireless booster is easier to place when cabling is not practical, but its performance depends on the signal it receives.

Yes, when the extender has an Ethernet port and its manual supports client connections. The PC then uses a wired link to the extender, while the extender still communicates with the router over WiFi unless it is wired upstream.