Could someone explain why we can’t just plug the average PC etc into a ‘raw’ internet line (like just entering a house) and have a mini modem on the motherboard do the translation work?
I know there’s a limit to IP addresses, and that it’s maybe easier to have a little box do the work where it enters a building.
… but apart from that?
I think you wonder whether your PC can be connected directly to the internet. Yes, like every server, router, firewall, technically you can. You would need to set up your connection completely manually, as there is no one doing that for you.
However, connecting millions of people is an epic task in itself. You would need at least as many public IP addresses as consumers have devices, and find a way to drag ethernet cables over enormous distances… while these won’t exceed about iirc 120m until signal loss is killing the connection. Then you would need all those consumers to have intricate network knowledge too.
Hence why we’re modems that can use long distance connections (like DSL over phone lines), that can arrange internal network connectivity without you having any knowledge, and apply internal IP space instead of public. Also your ISP can apply efficient internal routing and even internal IP space to save on rare and expensive public space.
There is much more to this, but I wanted to keep it ELI5. HTH!
So theoretically if you didn’t need more than one device at your end connected, you could (in theory) plug the internet cable straight into a pc. In theory.
Yes. In fact, that is what a server does. It is much like your PC, just heavily optimised for providing services (like websites) to many users. There is no modem between the server and the first router, just straight ip with the router as the default gateway.
You can. In practice
If you have two or more network adapters in your computer it can do network address translation to share your connection with your other devices that would use private IP addresses. If one of those network adapters is WiFi, your computer can act as a wireless access point.