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I'm not really knowledgeable about networking stuff, hence the stupid question. I read that ethernet was used for LAN connections but I'm pretty sure what I'm currently using to connect to the internet is 'ethernet'.

The only knowledge that I have about networking is that there are two types of internet connections: Dial-up and broadband. And broadband can be either DSL or cable. So where does ethernet come from?

The only thing I can tell is that I have a DSL model and there is an ethernet port at the back of it, a cable from which runs to a port in the back of my CPU.

So, can ethernet be used to connect to the internet? Is it a subtype of DSL? I'm really confused about this, so I would really appreciate if someone could explain this to me.

Also, I will apologize if this isn't the right place to ask.

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en.wikipedia.org/wiki/Ethernet in the german versions ist described as "originally" LAN –  bummi Dec 18 '12 at 9:50
@bummi The article only says that it was used for LAN, not that it means the same. –  slhck Dec 18 '12 at 9:52
Your modem and your computer form a LAN. Your computer uses Ethernet to connect to this LAN. Your router provides Internet access to every machine on your LAN. –  David Schwartz Dec 18 '12 at 10:16
LAN is to Ethernet as Power is to Copper wire. You need something to run the higher layer on, but it doesn't have to be Ethernet/copper, though it usually is. –  David Dec 19 '12 at 16:12

4 Answers 4

up vote 19 down vote accepted

You're confused about different concepts:

  • Network types such as LAN, WAN, etc. A LAN (local area network) means that your network is isolated to a certain area such as your home. In your case, that's anything between the router and your computer, or other computers that are in your house. A WAN (wide area network) for you is more or less "the Internet".

  • Internet access methods such as dial-up or DSL. These have nothing to do with the above. You can connect your LAN to the WAN through DSL or a dial-up modem, a mix between dial-up and satellite dishes, what have you. In essence it doesn't matter, and these methods have changed over time and vary between households.

  • Physical transmission such as Wi-Fi or Ethernet. Ethernet describes a physical way to plug devices together, e.g. with the classical Cat-5 cables you connect your computer and the router with. Ethernet was designed for LANs. Another physical access method would be connecting via Wi-Fi, for example. There used to be other network standards before, but Ethernet is the most widely used these days.

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+1 for clear disambiguation –  Karthik T Dec 18 '12 at 10:06
Makes sense. Thank you to you and everyone who posted! –  Alraxite Dec 19 '12 at 16:38

Both of your statements are correct.

Do you know how the term "Internet" came about? It is short for "internetwork" or "interconnected computer networks". So it is not a network itself, but a network of network.

This is how both of your statements that "ethernet was used for LAN connections" and "what I'm using to connect to the internet is 'ethernet'" are true. Your PC forms a LAN with your router via ethernet. Your router is INTERCONNECTED with other networks that forms the internet, so via the ethernet that connects you to your router, you are connected to the internet.

Of course this is not a highly technical answer but it should serve to get the idea across.

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The only significant difference between Ethernet, DSL, and "cable Internet" connections is how far they can reach – Ethernet cables typically are under 100 metres, while DSL connections can be several kilometres long, and fiber-optics lines – much more than that.

The difference between "Internet" and "LAN" is, in fact, really small – they both use the same IP protocols (IPv4 and IPv6). When a LAN is connected to the Internet, it becomes part of the Internet (which actually means a "network of interconnected networks").

So Ethernet can be used for connecting to the Internet as well. (The technologies used by DSL can be used to create a LAN, too.)

More precisely: Computers (and the modem) in your own LAN are connected over Ethernet, and the entire LAN is connected to your ISP using DSL. Your ISP then connects to the rest of the Internet over... I don't even know. Fiber?

There also exist many more kinds of connections that can be used for transferring Internet packets over – ISDN (not entirely unlike dial-up), InfiniBand, WiFi, GPRS/EDGE/3G (mobile phones), WiMax/LTE/4G (wireless connections), FireWire, and so on, and so on. Your "only knowledge you have" is somewhat incomplete.

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Think of how you connect your computer to the router. This cable is ethernet.

Cable / broadband etc are the cables coming to your house. This is not part of the LAN.

If you use wireless, you obviously don't use any cable in the LAN.

If on dial up, you plug straight into the phone line through a phone cable (which is not ethernet).

A little more detail (which I hope doesn't confuse matters).

Definition: Ethernet is a physical and data link layer technology for local area networks (LANs). Ethernet was invented by engineer Robert Metcalfe.

When first widely deployed in the 1980s, Ethernet supported a maximum theoretical data rate of 10 megabits per second (Mbps). Later, so-called "Fast Ethernet" standards increased this maximum data rate to 100 Mbps. Today, Gigabit Ethernet technology further extends peak performance up to 1000 Mbps.

Higher level network protocols like Internet Protocol (IP) use Ethernet as their transmission medium. Data travels over Ethernet inside protocol units called frames.

The run length of individual Ethernet cables is limited to roughly 100 meters, but Ethernet networks can be easily extended to link entire schools or office buildings using network bridge devices.


Now, as per the comments in my post, slhck correctly points out there is more to this, but you may be better off performing a Google search for "what is ethernet"

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In essence that's correct but "Ethernet" is usually more than just a cable. Your answer might benefit from explaining the different concepts of internet access (DSL, dial-up), physical access (wireless, wired), and network types (LAN, WAN, etc.). –  slhck Dec 18 '12 at 9:52
@slhck - I of course agree with you, but, if I go down this route of the deeper explanation, the OP will end so confused the answer won't benefit - I assumed the OP just wants a general overview. –  Dave Dec 18 '12 at 9:54

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