Ethernet In Big House

Yes, you are right; they are also often called network switch or gigabit ethernet switch. Here's an example: https://www.amazon.com/NETGEAR-GS105NA-Ethernet-Replacement-Unmanaged/dp/B0000BVYT3/ref=sr_1_4?s=pc&ie=UTF8&qid=1501276256&sr=1-4&keywords=ethernet+switch

That all depends. If your router has enough ports, why not just plug into that. If you need more ports a switch is a good idea. You could also use another router if you have one handy, just have to disable DHCP on it.

Hubs are to be avoided in all but the most simple of setups. They essentially just rebroadcast all incoming packets to every port.

Hub and switch are both technical terms and are *not* interchangeable. A 1Gbps 5-port switch can handle 5Gbps, but a 1Gbps 5-port hub can only handle 1Gbps so at worst each connection could be 1/5th (clearly if you had N ports then 1/N). So, you want a switch.

Now a router is a combination of a few things. One is a DHCP server, the other is an Ethernet switch. And odds are you'll have a WiFi access point built-in as well.

So, essentially you have two choices: Either get a router with enough 1Gbps Ethernet ports and locate it near your modem and hopefully somewhere that would lead to good WiFi access. Or get a router with at least one LAN side 1Gbps Ethernet port and run a cable to a 1Gbps Switch which could have 4, 5, 8, or more ports and then connect devices to the switch. Since the switch doesn't have DHCP, the IP addresses are assigned by the router and this process is automatic.

You could go a little off the walls and, for example, get a router with a 4 ports and run 4 cables out to 4 separate switches and then have devices plug into one of those switches. Of course you could have two switches, or three as well and could put switches connected to switches. There's essentially not a huge limit here, as you'd by default be allocating a 254 IP addresses so you could expand up to 254 ports.

Now one thing I must point out is that the switch does not isolate IP addresses. If what you're describing and hoping to achieve is to create two separate networks: one for the basement and one for the rest of the house, this isn't how you do that. (I'm in an area where rental properties often have two or three residences so perhaps you are thinking of renting the basement and providing Internet as part of the rent.) Therefore, devices connected via the basement switch would be able to see the other devices in the rest of the house. If you want to prevent that then you actually need two routers and you'd connect the second router to the first router like it were a switch except you'd have a cable from the LAN side of router #1 to the WAN port of router #2. The second router would get a local IP address from router #1 and would then hand out IP addresses on its LAN side which would include the basement client devices. So you might have some external IP from your ISP, then some internal IP like 192.168.0.10 handed out to router #2 by router #1 and then a basement device might have an IP address like 192.168.1.10 and be unable to see other devices connected to router #1, like 192.168.0.11 but can see other devices connected to router #2 like 192.168.1.11.