What Are the Internet, WWW, and the Web? A Plain-Language Introduction

Okay, so what is the internet?

 

It’s easier to understand if you follow how we got here. We used to have computers, and we had telephones. Computers could connect to the internet by dialing in over a phone line. If you lived through dial-up, it’s easy to associate the internet with the telephone.

 

Later, we started using Wi-Fi more and more. Now the internet seems to be everywhere, but the wire connecting us has disappeared from view. For younger people who never experienced that earlier stage, there may be a missing connection: what exactly does a telephone have to do with getting a computer online?

 

So we can start by thinking about paper cup telephones, then look at actual telephones. Take the field telephones you see in war movies: run a wire between the two ends, and you can talk. It’s easy to see how they’re connected.

 

Telephones also used to need operators to connect calls. You told the operator who you wanted to reach, and the operator connected the lines so the two of you could talk. These days, you might have to watch an old movie to see that happen.

 

Next, think about an ordinary home telephone. Pair a computer with a modem, and you could use the phone line to dial into the internet. Later, mobile phones became more common, and computers increasingly connected wirelessly. We gradually got used to going online without seeing a wire.

 

As dial-up internet became more widespread, WWW also started becoming part of everyday life. We’ll follow that thread, from telephones to how computers get online, and then to WWW.

 

We talk about going online and opening web pages, and we often see terms like WWW and Web.

 

There’s no rush to memorize the names. Let’s start with paper cup telephones and see if we can explain, simply, how one thing leads to another.

 

Quite a few of us probably played with paper cup telephones as kids, right? Two paper cups with a string stretched between them. One person speaks into a cup, and the other holds their cup near their ear and hears the sound.

 

What’s happening here?

 

When you speak, the sound makes the bottom of the cup vibrate. Those vibrations travel along the taut string to the other cup, making the air on that side vibrate, and the other person hears you.

 

A paper cup telephone gives us one idea to start with: a change you produce at your end can travel through a connection to the other end.

 

What about an electric telephone?

 

If you draw sound as a line, you’ll see it rise and fall over time. Electricity can vary in a similar way, going up and down like a stock chart.

 

So we can use changes in electricity to represent changes in sound.

 

You speak into a microphone, and the microphone turns the sound into an electrical signal. That signal travels to the other end, where a speaker turns it back into vibrations in the air, allowing the other person to hear you.

 

For now, you can think of a speaker as something that moves back and forth in response to a signal. It pushes the air, and we hear sound.

 

So the basic idea of a telephone is this: one end turns sound into a signal that can be sent, and the other end receives that signal and turns it back into sound. How sound recording and playback work

 

As long as the two ends can connect and know how to convert the signals, they can exchange information over a distance.

 

Next, let’s do one more thing: save that information.

 

We used to have vinyl records and cassette tapes. Later came CDs and audio files on computers. They record things in different ways, but they all allow sound to exist beyond the moment you speak.

 

You can say something today, and someone else can play it tomorrow. You can also copy and distribute the recording so more people can hear it.

 

At that point, you no longer have to personally repeat the message every time.

 

But how does a computer record sound?

 

First, imagine sound as a curve that continuously rises and falls. At regular, short intervals, we measure how high or low it is and record each measurement.

 

It’s a bit like checking a thermometer at regular intervals and writing down the numbers to see how the temperature changes throughout the day.

 

How much detail you can capture also depends on how you record it. If you can only record whole numbers, you have to choose the closest number you’re able to write down.

 

In a similar way, sound can become a series of numbers that a computer can store and process. That’s the general idea behind turning sound into digital data.

 

During playback, equipment turns that data back into a signal that can produce sound.

 

You can think of it this way: the height that used to run vertically along the curve now has to be represented by a series of numbers laid out horizontally. It’s a bit like taking something upright, laying it down, and arranging it one piece after another along a timeline.

 

You might ask: doesn’t laying it down make it longer? Suppose the height we could originally represent in one position now has to be split into eight positions and sent one after another. Wouldn’t a word that originally took one second to say now take eight seconds to send?

 

Yes. If each position takes the same amount of time, eight positions will take eight times as long.

 

The answer is that electrical signals travel far faster than sound, and they can change repeatedly in a very short time, sending those positions out quickly.

 

Light travels about 300,000 kilometers per second. For an electrical signal in an ordinary wire, you can think of roughly 200,000 kilometers per second. Sound in air travels about 340 meters per second—a difference of hundreds of thousands of times. How fast electrical signals travel through wires, the speed of sound in air

 

So although laying things out horizontally increases the amount we need to send in sequence, we can make the time taken by each position very short. We can send one second of sound in far less than a second, then play it back at its original one-second pace after it arrives.

 

Streaming works this way too. You receive data while playing it. As long as the data keeps arriving faster than playback uses it up, the upcoming sound can be ready in advance, waiting for its turn to play.

 

Imagine someone quickly sending you the words you’re about to read aloud. You then read them one by one at your normal speaking pace. Transmission runs ahead, and playback follows at its own pace. A longer sequence of data doesn’t have to stretch the sound out to eight times its original length.

 

At this point, we have two ideas: information can be turned into signals for transmission, and it can also be saved as data to be copied and sent later.

 

Now we can get to networks.

 

If only two devices need to exchange data, connecting them directly is easy to understand. But what if there are lots of devices?

 

You can’t run a dedicated line from your home to someone else’s every time you meet a new person, can you?

 

So we first connect devices to equipment in between that forwards data. Through that equipment, we can send data to other places.

 

Different networks can then connect to one another, allowing the whole thing to keep growing. For now, you can understand the internet as a system formed by many interconnected networks.

 

Those connections may use wires, or they may be wireless. MDN’s explanation of the internet

 

It’s a bit like flying.

 

Suppose you’re traveling from Taiwan to the United States. You go from home to the airport, fly over, then travel to your destination. You might take a direct flight, or you might need to transfer.

 

Sending data involves a similar idea. Your computer doesn’t necessarily connect directly to the other person’s computer. The data may pass through several devices that forward it along the way.

 

But sending data over a network is a little different from having your whole body travel on the same flight.

 

Data is usually split into many small pieces for transmission. Each piece comes with the information needed to send it, so the equipment along the way knows where to send it next.

 

It’s like mailing a package. You write down the address, and the package passes through different transfer centers before finally reaching the recipient.

 

The address needs to be somewhere everyone knows to look, so the transfer centers know where to send it. If part of a shipment doesn’t arrive, there also needs to be a way to notice, ask the sender to resend it, and put everything in order at the end.

 

Computers need to handle these things when sending data too. For now, it’s enough to know what they’re busy doing. There’s no rush to memorize every name. Cloudflare’s explanation of packets and network protocols

 

So what is WWW?

 

WWW stands for World Wide Web. In Chinese, it’s usually called 全球資訊網, and it’s also often simply called the Web. These names all refer to the same thing.

 

The word “web” can mean a spider’s web. Imagine one document linking to another, which in turn links to more documents, eventually forming a web that stretches around the world.

 

There is something a little romantic about the name. But the connections we’re talking about here are simply the links we click every day.

 

You open an article, click a link in it, and jump to another article—or even another website.

 

So we need to understand the internet and the Web separately.

 

The internet allows devices to send data to one another. The Web builds on that foundation, letting us use web addresses, browsers, and links to open web pages and access their contents.

 

It’s a bit like the relationship between roads and a delivery service. Roads allow things to move from one place to another, while a delivery service uses those roads to deliver what you want to send.

 

Other services can use the same roads too. Email, online games, and internet calls all use the internet, but that doesn’t mean we can call all of them the Web.

 

If you open a webmail page in your browser to check your email, you’re using an email service through the Web. MDN’s distinction between the internet and the Web

 

So what actually happens when we open a web page?

 

Suppose you enter a website’s address in your browser.

 

The browser first needs to know where to find that website. You can think of this as looking someone up in an address book: you remember their name, but you still need to find the address where you can actually reach them.

 

Once it finds the location and establishes a connection, the browser can make a request.

 

For example: I’d like to see this page.

 

The computer at the website’s end receives the request and sends back the data needed. Once the browser receives it, it displays the text, images, and layout in front of you.

 

It’s a bit like ordering at a restaurant. You need to let the staff know what you’re ordering, and they need to let you know whether the dish is available and whether they can serve it.

 

The browser and the website also need a way that both sides understand to make requests and send back responses. MDN’s explanation of how a web page loads

 

As for how the underlying data actually gets sent, there are different ways of doing that. It’s easier to keep things straight if we first separate “what I’m asking for and what comes back” from “how the data gets there.” The HTTP/3 specification

 

Next, we come to HTTPS, which you often see at the beginning of a web address.

 

Suppose you order an expensive designer handbag. For shipping, it would usually be packed in a box so people along the way can’t see what’s inside.

 

The way HTTPS protects the contents being sent is a little like that. An ordinary cardboard box is easy to open, though, so it only helps us picture the idea.

 

What HTTPS actually does is turn the contents being sent into a form that’s difficult for outsiders to understand even if they get hold of it. It also makes it possible to detect content that has been secretly changed along the way.

 

The other party’s identity is also checked when the connection is made. You can think of it as checking, before sending something, that the recipient is the one you meant to reach.

 

For example, when you enter a password on a website, that data needs this kind of protection as it’s sent.

 

But the outside of a box still needs delivery information. Likewise, using HTTPS doesn’t mean the entire connection becomes completely invisible.

 

It also doesn’t guarantee that the website’s content is trustworthy. A well-protected package doesn’t mean every word the sender says is true. The focus of that protection is the data being sent between you and the website. MDN’s explanation of HTTPS

 

Finally, let’s put all of this back into one example.

 

Suppose you record an introduction, save it as an audio file, put it on a website, and send a friend the link to the page.

 

Your friend clicks the link. Their browser finds the website and requests the web page and audio file over HTTPS. The data travels back over the internet, passing through the equipment in between, and your friend’s device plays it.

 

You don’t need to speak into the microphone again at the moment your friend clicks the link. They’re getting data you saved earlier, and their device turns it back into sound.

 

That’s why people in different places can open and listen to a recorded introduction at different times.

 

That’s what an explanation of how the internet works looks like when you walk through it piece by piece.

 

But now that everything is wireless, with invisible signals flying through the air, honestly, it’s become hard to see this web at all.

 

At least, you can’t see it in your everyday surroundings.