How Does the Internet Work?

Many users do not understand how they are able to connect to the Internet, and just where all of that information is. Let’s discuss first, what is the Internet? The Internet is a vast array of computers, some huge, some small, many midsize, and all in between. All of these computers house some sort of data, and host applications for others to use. Those computers are connected to a backbone network, provided by what’s called an ISP, or Internet Service Provider. Your cable company or phone company is likely your ISP. So now we have a bunch of computers, connected to backbone networks, talking to each other, and asking for services from one another. In the simplest terms, that IS the Internet. Things like YouTube, Google, Yahoo!, and Twitter are all hosted on computers (several though in reality.) Now that we know what the Internet is, let’s talk about how YOU connect to it.

As we said before, you connect to the Internet using an ISP. The ISP provides you a device, called a modem. A modem is short for modulator/demodulator, and simply converts digital signals to analog, and vice versa. It is the device which connects to the ISP and allows you to connect your own devices at home. Essentially, it is your internet connection. You may plug a router into it, or even just one PC. Typical homes today use routers, to connect many different devices, and even some wirelessly to the network. This is called a LAN, or Local Area Network. Everything in your house, not including the modem, is YOUR network.

Let’s say for example, you have two computers in your home, and a router. Computer One is plugged in that router, and Computer Two is a laptop that connects to the router via wireless network. That is the LAN, as explained above. Now, outside of those devices, from the modem to the cable companies equipment is called the WAN, or Wide Area Network.

Let’s sit down at Computer One and go to Facebook. Your computer, connected through your LAN, sends data through the WAN as soon as you type www.facebook.com and hit . Facebook’s computers, or in this case, servers, since they “serve” data, receive the request and send the webpage and data back to your ISP, and finally back to you. This all happens in a matter of a few milliseconds. Your modem sends this data to the router, and the router sends it back to Computer One. And that’s how trillions of web requests are handled daily.

You might say “trillions!!?” Yes, it’s a lot. And there’s a concern called network congestion that comes into play here. Suppose you have 100,000 computers all trying to talk to Facebook at once, in the example above. The server at Facebook can handle only so many connections, and may queue the ones it cannot handle. Thus, your request may sit in the queue for a few seconds before the web page appears. And that explains why some web pages do not always immediately appear.

One other way we mitigate network congestion is called routing and switching. Routers are devices that are located all over the Internet, and in homes, and decide what communications or network path is optimal for a packet of data to take, in order to quickly do its job. Routers are a bit of a complex subject, but for now compare it to one of those old-time telephone switchboard operators. Now think of it as an old-time switchboard operator with 1000 arms and can make a patch in milliseconds, all while using a patch panels with thousands of plugins.

Computing and the Internet are revolutionary resources for humanity, and understanding them a bit better each time you use one will only make your experience that much better.

Here’s a list of common network devices and what they do.

Hub: A hub is designed to allow a number of different devices to connect to one outgoing cable. For instance, if you have 4 PC’s located in one room, you could use a hub to connect them to one cable that leaves the room. The drawback is that hubs are not smart, that is, they cannot do any advanced networking, such as routing. Some hubs are a bit more intelligent, but a hub is not a replacement for a router. If you connected your 4 PC’s to a hub, and then connected the hub to a modem, it would not work.

Switch: A switch is a smarter hub. Switches are used when many computers, typically 12 or 24, must connect to one cable leaving the area. Switches are used in office environments because they are a bit smarter, and can do a bit of elementary routing. Layer 3 switches, for instance, can route packets via the Networking Layer of the OSI model, making them somewhat useful. Still there’s a better option.

Router: A router does what its name implies; it routes data and packets. It can decide which way to send something. It can also decide how much to send, versus sending another amount a different way. Routers come in many different sizes and capabilities, but the bottom line is that routers are what are used behind residential modems to connect many different devices. The router is often the central device in a LAN.