>>717062864
that's what brings the internet into your house, the phone line.
Ethernet ports in your house would come off the router. In newer houses the router tends to have its own dedicated port in the electrical closet and the house would have the Ethernet wiring built in already meaning all you'd have to do is swap out the router depending on who you have as an ISP, but I'll assume yours is an older build so the router needs to be freestanding. If you're lucky your house might 1. have landline ports already built in, and 2. it's at least Cat5e (which if your house was built in this century, it almost certainly would). If you have those ports, you could track down where those wires all merge so they could be hooked up to the phone back when people had landlines, and instead set your router up there.
if you're unlucky and have none of this, you'll have to either custom-wire the walls, have snakes running around out in the open like a hacker cave, or just live with WiFi.
