How Does the Internet Work?

As we explained in our What is the Internet and History of the Internet articles, the Internet is a collection of interconnected computers and computer networks that allows information to travel between any number of connected points.  It works because all networks have adopted a free-form way of transmitting information (packet switching) and a standard way to communicate with each other (TCP/IP).  This article will get a bit more into detail about how the Internet works for you as an individual user.

Connecting to the Internet

To connect to the Internet, your computer must be connected to a modem, either through a cable or a wireless radio signal.  Short for "modulator-demodulator", a modem converts information from your computer into a signal that can travel along the Internet, and in turn can convert incoming Internet signals into information that your computer can understand.  Many modems are provided by Internet service providers (ISPs), telecommunications companies that provide Internet connectivity.  Common ISPs include AT&T, Comcast, Time Warner Cable, and Verizon.

When you connect to the Internet, your computer is given a unique number that helps identify it out of all of the other things on the Internet.   This number comes in the form (X . X . X . X), where each "X" is a number between 0 and 255.  This is called your Internet Protocol address (or I.P. address).

Connecting to another point on the Internet

When you want something from the Internet, whether it's to download a file, look at a web page, or just talk to somebody else, you need to connect to that point.  When you're initiating a request to connect to a point on the Internet, that makes your computer the "client", and it makes the other point the "server" (or sometimes "host").  Points in-between that direct how communication flows back and forth between the two points (remember, with packet switching, information can take multiple paths on the Internet) are called "nodes".

For one thing, you need to know how you want to connect to a point on the Internet.  We mentioned that all Internet networks use TCP/IP as a standard, but there are sub-protocols that denote certain actions that you want to take over the Internet.  For example, as we discussed briefly in some of our previous articles, common sub-protocols include HTTP ("hypertext transfer protocol", for when you want to view a web page on the World Wide Web), VoIP ("voice over Internet protocol", for when you want to make a phone call over the Internet), and FTP ("file transfer protocol", when you want to move computer files back and forth between two computers on the Internet). 

Many services that use these protocols are designed to take care of the heavy lifting for you; for example, many web browsers allow you to type in "www.example.com" without the "http://" bit, and they will fill the protocol in automatically for you.

For another thing, you need to know where you want to connect to on the Internet.  For example, if you want to connect to a specific computer, you need to know that computer's I.P. address.  Or, if you want to view a web page on the World Wide Web, you need to know that web page's U.R.L. address (see our What is a URL article for more information). 

Again, many services can help take care of the hard part for you.  For example, search engines can help you find the URL for a specific web page by displaying the content that's there.  Also, many email and VoIP services have an email address or user name stand in for an I.P. address, which makes finding a specific person much easier to understand for you as a human!

 

That's a brief explanation of how the Internet works when you use it!


History of the Internet

In our What is the Internet article, we touched briefly on where the Internet came from.  But you may still be wondering: "Who exactly invented the Internet?  And when was the Internet invented?"  These questions are somewhat difficult to answer, because the Internet as we know it is the result of a coming-together of several different technologies that were developed by different people at different points in time.  This article will give you a brief overview of the important events and people that made the Internet what it is today.

Early inspiration and "ARPANET"

One of the first people to think about a global computer network was J.C.R. Licklider, an American computer scientist working at the Advanced Research Projects Agency (A.R.P.A.) at the U.S. Department of Defense.  He had written papers in 1960 and 1962 about a worldwide connection of computers that would mimic modern libraries, allow for rapid information storage and retrieval, and perform other functions in harmony with humans.  The main problem that Licklider ran into, however, was how to connect computer systems without needing to have a different computer dedicated to connecting to each different point in the network.

The answer was a technology called "packet switching".  It allowed information to be split up along a network and move to where it needed to go independently, without needing a direct one-to-one connection.  Some early pioneers of this method of information transmission included Paul Baran, Donald Davies, and Leonard Kleinrock.

Meanwhile, after Licklider had left A.R.P.A. in 1964, two computer scientists named Robert Taylor and Larry Roberts decided to pick up where he left off.  Applying the technology of packet switching to Licklider's idea for a free-form computer network, they created the ARPANET.  Running using the "Request for Comments" protocol developed by Steve Crocker, ARPANET's first successful transmissions were made to the Stanford Research Institute on October of 1969.  ARPANET served as the technical blueprint for the modern Internet, and became the inspiration for several other independent packet-switching networks, such as X.25, the Merit Network, CYCLADES, and Usenet.

Transfer Control Protocol / Internet Protocol (TCP/IP)

The emergence of several new packet-switching networks resulted in a new problem: they all used different protocols.  This meant that computers on a network could communicate with each other, but not with computers on any other network.  The solution, then, was to create a standard operating protocol that all networks would use. 

This task was taken on by Robert E. Khan of A.R.P.A. and Vinton Cerf of Stanford University.  Building on the foundations of the CYCLADES network from France (designed by Hubert Zimmermann, Gerard LeLann, and Louis Pouzin), they created the specifications for a protocol that would make it the responsibility of computers themselves, rather than the network connections, to have the right credentials.  This would make it possible for any network to connect to another. 

With the blueprints written in 1973-74, Transfer Control Protocol / Internet Protocol (TCP/IP) was put into practice in 1978, and was adopted in the early years of the 1980s.  By 1983, TCP/IP had become the standard network protocol for ARPANET.

New players and commercial applications

Up until about the 1980s, ARPANET was restricted to military and academic uses.  That all changed when computer equipment companies and other American government branches began researching and setting up their own TCP/IP-based networks.  One of the key players in this regard was the National Science Foundation (N.S.F.), which created the Computer Science Network (CSNET) in 1981 and its successor, the NSFNET, in 1986.  The goal of the NSFNET was to connect the networks of American universities and colleges, not only with each other, but also with smaller regional education hubs.  At around the same time, the European Organization for Nuclear Research (C.E.R.N.) was undertaking the same types of activities in Europe, and expanding into the Pacific world.

In the late 1980s, the first commercial Internet service providers (ISPs) were formed.  Though they initially met stiff resistance from the scientific community, which was eager to preserve an Internet that was designed to cater to its needs, commercial ISPs gained acceptance throughout the 1990s.  This was aided by the 1992 Scientific and Advanced Technology Act, which allowed the N.S.F. to permit research and education institutions to connect to networks that were not necessarily dedicated to education or research.  The last barriers to commercial Internet usage fell with the shutdown of the two major proprietary networks, with ARPANET closing in 1990 and NSFNET closing in 1995.

 

And that's a quick version of how the Internet, in the form we recognize it to be in now, was formed!


Where is the Internet?

With all of our talk about the Internet being this gigantic computer network that spans the globe, you may be wondering: "where does the Internet actually live?"  Indeed, the Internet isn't some kind of abstract thing floating in another dimension that somehow magically lets you look up what the weather's going to be like tomorrow.  The Internet does have physical components; it's just that there are lots of them, and some of them are more readily visible than others.

Server computers

These are a special type of computer that exist primarily to store and let other computers retrieve and/or use various Internet-related functions.  These include websites and web pages, communication (text chat, phone calls, or video chats), and file transfers.  The Internet is estimated to be made up of over 75 million of these types of computers.

Cable infrastructure

How do all of those computers stay connected?  The same way telegraphs and other telecommunications networks stayed connected: lots and lots of cables!  There are over 550,000 miles of fibre-optic cables running along the ocean floor right now in order to connect the server computers that form the backbone of the Internet.  Some of the biggest hubs where these cables meet up include Tokyo in Japan, Hong Kong, New York City, and Cornwall in the U.K.

Modems

These are the personal devices that allow individual computers to connect to the Internet.  They used to work using phone lines, but with the introduction of new types of cables and protocols, that isn't necessary anymore.  In fact, many modems nowadays don't need a physical connection in order to provide access to the Internet; they can send and receive wireless signals.  This is what you'll often hear referred to as "wi-fi".  Many homes and public buildings have this type of modem installed, and even some cars are starting to include wireless modems!

Your computer 

Yes, even your computer is part of the Internet, as long as it's connected!  This could be your desktop computer, mobile smart phone, or tablet computer (such as an iPad).  It connects to the Internet with a unique address, and can send information out into the Internet as well as retrieve it.  There are even some Internet-capable computers being released have their own modems built in, and some that you can wear like clothing or accessories!

 

So, when someone asks the question "where is the Internet?", the answer may one day be "everywhere!"


Internet Glossary

There are lots of terms associated with the Internet that are unique, confusing, or just downright strange.  We've gone over a few of them in our earlier tutorials, but here's a more complete list of some of the common Internet-related terms you'll hear.

Common Internet and World Wide Web terms

Blog — short for "web log", a website or service that allows someone to periodically record their thoughts, feelings, and opinions, similar to a diary or journal.  Many are text-and-picture, but some are made of video or audio recordings.

Bookmark — Also sometimes called a "favorite", a web page that one has instructed their web browser to record the address of, so that they can easily access it later.

Client — A computer connected to the Internet that asks for information from somewhere else on the Internet, whether that's a web page, a computer file, or communication from another person.

Cloud — A term used to refer to networks of server computers on the Internet that, instead of storing web pages, store computer files or information for running applications that would be too large or inefficient for a single computer to store on its own.  The term refers to the idea that this information is floating freely through the Internet, like a cloud, and can be accessed from any client computer (with the right credentials, of course) and from any server within the group.

Cookie — A small computer file that some websites will place on your computer when you visit them or interact with them in some way.  It is a website's way of remembering you, so that it can provide you with personalized services the next time you visit.

Domain — General term referring to an area of the World Wide Web that contains a unique website (or websites).

E-commerce — Usually refers to a website where goods and services can be bought or sold.  Common examples include Amazon and eBay.

Forum — A website, or component of a website, that allows people to create and contribute to discussions about particular topics by posting a series of messages.  Also called a "message board" or "bulletin board service (B.B.S.)".

FTP — Stands for "file transfer protocol".  A set of instructions that your computer uses when it wants to transfer computer files between itself and another computer.

HTTP — Stands for "hypertext transfer protocol".  The set of instructions that your computer uses (via your web browser) when it wants to look at a web page on the World Wide Web.  The more secure version is "HTTPS".

Hyperlink — A word, phrase, or image in a document or web page that you can click to take you to a different part of the same document or web page, or to a different web page.

Internet — A worldwide series of connected computer networks that allows for the sending and receiving of information between computers or networks.

IP Address — Short for "Internet Protocol address".  A set of four numbers, each between 0 and 255, that uniquely identifies a computer when it connects to the Internet.

ISP — Short for "Internet service provider".  A telecommunications company that provides you with a connection to the Internet.  Common ones include AT&T, Comcast, Verizon, and Time Warner Cable.

Modem — Short for "modulator-demodulator", a device that lets you access the Internet by turning information from your computer into a signal that can travel along the Internet and vice-versa.

Node — A computer or other device (such as a router) that directs the flow of information on the Internet.

Phishing — Refers to when criminals attempt to steal personal information over the Internet, or trick people into downloading a malicious program onto their computer, by posing as a trusted person, business, or organization.

Search engine — A website that allows a person to find web pages and other content on the World Wide Web by matching them with key words or phrases, and sometimes other specialized criteria.

Server — A special type of computer whose role is to store and give out computer files on the Internet, or information related to websites or web pages.

Social network — A general term used to describe a website or other Internet-based application that allows individuals, companies, and organizations to connect with and broadcast information to one another, among other functions.  Also often referred to as "social media".

Spam — Refers to when trivial information is sent in bulk to people over the Internet, usually through email, with the sole intention of annoying them or slowing down their computer or Internet connection.

Streaming — A computer technology that makes media files (such as videos and songs) available as they load, as opposed to having to load them entirely and then play them.

TCP/IP — Stands for "transmission control protocol / Internet protocol".  A standard set of instructions that allows computer networks to connect to each other and form the Internet.

U.R.L. — Stands for "uniform resource locator".  An address that helps uniquely identify a web page or other document on the World Wide Web.

VoIP — Stands for "voice over Internet protocol".  A set of technologies and processes that changes analog voice signals to digital computer signals and back again, allowing people to make phone calls over the Internet.

Web 1.0/2.0 — Generally efers to the distinction between static and dynamic websites.  Static websites appear in a web browser exactly as they are stored, and often can't be interacted with much.  Dynamic websites run background processes that allow them to be updated in some ways with or without a user's actions, often without needing certain web pages to be reloaded from their servers.

Web browser — A program that allows a person to access the World Wide Web by asking for website or web page information from server computers, displaying that information, and allowing the user to move from one website or web page to another by clicking hyperlinks.

Website — A collection of multimedia documents on the Internet, usually connected by hyperlinks, that share the same (or a similar) domain.  Sometimes just referred to as a "site", for short.

Wi-Fi — A technology built into many modern modems that allows them to provide Internet connections over short-range radio waves.

Wiki — A type of database website in which information is able to be contributed, edited, or removed by anyone who accesses the website.  Dedicated wiki users often discuss the validity of added or edited information, and make corrections where necessary.

World Wide Web — A network of interconnected documents containing written information, photographs, animations, videos, sounds, games, etc. that is accessed through the Internet.  Often abbreviated as "w.w.w." or "the Web".


Advantages and Disadvantages of the Internet

If you've been following our tutorials up until now, we've shown you some of the many things that can be accomplished using the Internet.  So that means the Internet must be pretty great, right?  Well, it is an extremely useful invention, but like most things in life, using the Internet in the wrong way can lead to bad things happening and other unintended consequences.  The following is a list of some things that people have pointed out as being good or not-so-good about the Internet.

Advantages of the Internet

Faster and more widespread communication

One of the biggest advantages of the Internet is that it has vastly increased the speed and scope of communication.  A letter that could have taken days or weeks to reach someone a few towns or cities over now takes only a few minutes (or sometimes seconds) with email.  Plus, with the Internet being a more-or-less worldwide network, one can keep in touch on a fairly regular basis with loved ones who are on vacation in the Mediterranean, or even connect and make friends with people living in Africa or Asia!

Massive information resource

The World Wide Web was designed to be the ultimate library, and many people use it in just such a manner.  Whether one is trying to complete a school project or academic paper, trying to find out about a product or service that will help them out in life, or just looking for trivia on something they enjoy, chances are that the World Wide Web has the information they need.  And, if one doesn't exactly know what they are looking for, search engine websites can help point people in the right direction by matching key words or phrases to content on specific web pages.

More convenient services

Many common and essential services have moved to the Internet in order to make themselves accessible and convenient to people.  For example, many banks allow their customers to complete their transactions online, instead of having to visit their actual branches during normal business hours.  In addition, there are several companies and e-commerce websites that allow people to buy and sell goods, and then ship them off or have them dropped off without them ever having to leave their homes.

Instant-access entertainment

Just because the Internet is one of the greatest technological inventions of our time doesn't mean that we can't have a good time with it!  There are plenty of games that can be played on or over the Internet, plus many movies, TV shows, and songs that can be watched, listened to, or downloaded over the Internet.  Another advantage is that many of these things are "on-demand", meaning that you can access them immediately, and you don't have to wait for them to become available at a certain time.

Making things easier and quicker in everyday life

As we discussed in our The Internet of Things article, people are beginning to adapt the connectivity principles of the Internet to objects that we use in everyday life.  The Internet is helping people monitor their health, keep their cars safe, locate their lost pets, manage the lights and locks in their homes, or even access the World Wide Web just by wearing glasses or a watch!  Companies are looking for new ways to integrate the Internet into our lives, and are finding more applications for the Internet every day.

Disadvantages of the Internet

Information overload

We've already pointed out that the Internet is a great resource for information.  Unfortunately, it has become so easy to put information on the Internet that a lot of it overlaps and is needlessly redundant.  Just try typing "how to fix a leaky faucet" into a search engine, and you'll probably find at least 25 different websites that show you how to do it.  Also, just because information is available on the Internet doesn't mean that it's necessarily reliable; it may not be fact-checked or cited with proper sources. 

Worst of all is when people use this information overload as a weapon to slow down people's computers or Internet connections ('spam') or trick people into doing something dangerous online by pretending that their information is legitimate when it's really not ('phishing').

Lack of personal interaction

Sure, people can communicate in various ways over the Internet, such as sending instant text messages, emails, video messages, phone calls, or video chat.  But psychologically speaking, none of these things are a substitute for talking with someone face-to-face.  Studies suggest that people who use the Internet to socialize rather than hanging out with people in real life are more likely to feel lonely and isolated.  This is especially true if they simply broadcast what they're feeling and don't take the time to actually engage in a discussion with someone.  Maybe those "social networks" aren't so "social" after all.

Anonymity

This one is somewhat of a mixed bag.  In some cases, anonymity on the Internet is useful in that it keeps people safe from criminals and authoritarian governments when they do legitimate things like online banking or chatting with their loved ones.  On the other hand, anonymity on the Internet also opens the door for criminals to conduct business without anyone being able to identify them as actual people.  On a smaller scale, the convention that many websites and Internet-based applications use of allowing people to be identified by "user names" (such as "MisterBlaster421") has led many to send intentionally insulting and offensive information to others over the Internet.  The idea is that, since these people are only known by their user names and not by their real names, there will be no real-life consequences to being disrespectful towards others on the Internet.

Few moral checks on content

While there are some national and international laws that prevent access to certain content, in general, there are few limits on what people of any age or maturity level can post or find on the Internet and World Wide Web.  This includes subject matter that is overly sexual, violent, or hateful and offensive in nature.  While there are some websites which host this type of content that are responsible enough to require people to pass age checks in order to access them, many others don't.

Risk to personal information

There are many websites that require you to input personal information in order to use them.  This may be because they need your billing and/or address details if you're using them to buy or sell things, or maybe just because they want you to prove that you're a real person and not a computer program that someone cooked up to cause trouble.  Or, sometimes, you may reveal personal information about yourself voluntarily, such as if you are chatting with friends over the Internet or are filling out a profile on a dating website or other social network. 

While this is usually either a harmless exercise or one that is protected by a bunch of security measures, there is always the unfortunate risk that criminals may be able to find this information and use it to profit at your expense… or at least your embarrassment.

 

Again, whether the Internet is good or bad largely depends on whether or not it's used properly.  Though some people use the Internet carelessly or for insidious purposes, most people do use the Internet as it was intended to be used.  As long as you're smart with how you use the Internet, its advantages will almost always outweigh its disadvantages, and you'll find that it's an invaluable tool for helping you with some of the main activities that you do every day.