The Internet
This tutorial provides an overview of what ‘The Internet’ is, how it works, and the technologies underpinning it.
Whether you are new to ‘The Internet’, or have been surfing the web for years, an understanding of the technologies that make ‘The Internet’ work will increase your confidence online and likely save you hours of calls to tech-support.
This tutorial will also help you to make sense of the technical jargon you will certainly encounter along the road to online success.
By taking the time to absorb this tutorial you will gain the technical understanding necessary to communicate and collaborate with technical experts, contractors and ‘internet natives‘.
What exactly is ‘The Internet’?
The Internet is an international network of computers that communicate using the open-source TCP/IP protocol popularized in the late 1980s. The word ‘Internet’ derives from later half of this networking protocol’s full name which is Transmission Control Protocol / Internet Protocol.
Network protocols are standards used by hardware to communicate with each other and define how the hardware encodes and decodes information represented in binary. The best analogy for binary is the common household light switch. The ‘On’ state corresponds to a 1 in binary, and in networking a positive voltage on the copper cable. The ‘Off’ state corresponds to 0 in binary, and the absence of a voltage or reference signal on the line.
Prior to TCP/IP gaining widespread support the networking of computers was dominated by proprietary protocols whose license fees made the technology prohibitively expensive for home users. Eventually the popularity of TCP/IP was responsible for it becoming the standard protocol for computer network communications in spite of it’s technical inferiority.
Internet Protocol
Internet Protocol (IP) breaks up transmissions in to little chunks called ‘packets’ that are able to independently traverse the network in search of their destination. It also defines the method by which the recipient can reassemble the packets to form the original message and determine if any packets are missing. This technology was originally developed by the US Government’s Defense Advanced Research Projects Agency (DARPA) as a solution to ensuring transmissions were always delivered.
Internet Protocol’s advantage derives from its ability to determine the best route during the transmission’s propagation. This means that if a communication node, like a switchboard or a radio tower, is unavailable, too busy or destroyed, then instead of the message being lost, the transmitting node continues cycling through alternatives until a viable recipient is found. Applying this protocol throughout an entire network practically guarantees delivery of the message because the transmission route is variable unlike the traditional point-to-point communication protocols used by the original telephone networks where the transmission’s route is fixed.
IP Addresses
In much the same way as the postal service knows where to deliver your mail by reading your street address, Internet Protocol (IP) defines addresses using specially formatted numbers called an IP address. Understanding the basics of IP addresses is important because they are fundamental to how the Internet delivers information.
The Internet Protocol requires that IP addresses must be unique for each connection to the network. Your IP address is your computer’s online identity and this ID is how the network is able to deliver the right information to the correct computer.
Unless you’re a telecommunications company with an international backbone, IP addresses are comprised of four sets of three decimal numerals separated by periods, e.g. 121.050.321.457 Each set of three numeral identifiers comprise a class, so there are four classes labeled A through D. In our example address 121.050.321.457, the A-class identifier is 121, and the D-class identifier is 457.
Since every IP address must be unique within a network some addresses are allocated to avoid duplicates. Globally, A & B classes are allocated to countries by the Internet Assigned Numbers Authority (IANA). The C-class addresses are allocated by each country’s own national authority to Internet Service Providers (ISPs). Although allocations haven’t followed class strictly since 1993 common use of class has endured because it continues to provide a generally accurate description of the allocation process.
In the final step your ISP allocates your connection a unique IP address from within its allocated range when you connect to the Internet. This kind of address, that changes every time you disconnect and reconnect to the Internet, is known as ‘dynamic’ addressing in contrast to a ‘static’ address where an IP address is fixed. Static IP addresses are typically reserved for servers and communication nodes where it is necessary to fix an address, however other than these exceptions, dynamic addressing is usually preferred.
Local Networks
While it is true that IP addresses must be unique you will often see the default IP addresses 127.0.0.1 and 192.168.0.1 and may wonder, “Why doesn’t that cause problems with duplicate addresses?”
The reason they don’t is because the ‘local-area network’ (LAN) is separated from the ‘wide-area network’ (WAN) a.k.a. ‘The Internet’. So as long as the IP address is unique within the local network there are no duplicates and no problem. In fact the same principal applies to ISP’s and is utilized by them to ensure an IP address is always available in spite of the limited number actually available.
In 1998 the Internet Engineering Task Force (IETF) published a new version of Internet Protocol, IPv6. Version 6 makes many improvements over the current Version 4 including vastly increasing the number of IP addresses available. Version 6 has not yet been widely adopted however. Its lagging adoption is attributed to the existing investment in legacy (IPv4) hardware and the use of Network Address Translation (NAT) techniques that reduce demand for new addresses.
Uses for Internet Marketers
As an Internet Marketer it is often useful to log the IP addresses of visitors to your website. Often this information will be logged by your web server so it can often be relatively simple to obtain this information. Website analytical software can be used to assist in interpreting this raw log data, and a basic analytics software is often included in web hosting packages.
Also because many people understand IP addresses to be an online identifier, IP addresses are sometimes displayed to purchasers during the checkout process to discourage fraud. Furthermore since allocations of A & B classes are made according to country, and C-classes are specific to an ISP, IP addresses can be used to determine geographic location.
By understanding the geographic location of visitors and buyers it is possible to assess the relative effectiveness of local marketing tests and refine your offering to suit a geographic niche market. A reliable geo-location service that provides a free live demonstration is IP2Location.com.
The World Wide Web
In 1989 Tim Berners-Lee came up with the idea of ‘hyper-linking’ documents and 18 months later he created and coded the standard protocol we all now use to ‘Surf The Web’, http. You will be familiar seeing ‘http’ since it precedes practically all ‘web addresses’ more formally called Uniform Resource Locators (URLs). Here is a video of Tim where he tells the story of how he invented the World Wide Web in his own words.
Whenever you click a link, or enter a web address, you are transmitting a request. The specifics of the request is defined by the Uniform Resource Identifier (URI) and a URI has four parts,
- the protocol: http://
- the domain: www.google.com
- the path: /tutorials/
- the query-string: ?r=123
You can forget about the query-string and the path for now and focus on the URL which comprises the first two parts, the protocol and the domain.
The protocol part of the URL informs both the client and the server what type of information to expect and to what to send. In the case of valid http requests, the response will be compliant Hyper-Text Markup Language (HTML) code which your browser interprets to display the requested web page. The domain part of the URL is converted to an IP address behind-the-scenes using another one of Berners-Lee’s inventions called the Domain Name System (DNS).
Whenever you make a request by typing a URL, or clicking a link, DNS software running on servers at your ISP translates the domain part of the URL in to the IP address of the server hosting the website for that domain. In fact you can type the IP address in to your browser directly and it will work just the same on many websites including this one. Try it for yourself by clicking the following link http://96.0.108.187/speaker-reviews/brett-mcfall/
File Transfer Protocol
While you will almost always use the ‘http’ protocol online, you should also be aware of ‘ftp’. File Transfer Protocol is another protocol that is better than http for uploading and downloading (transferring) files, and is fairly common. You can view ftp sites like the Usenet FAQ archive in a browser, however using ‘FTP client’ software like FileZilla (open-source & free) is recommended.
Key Concept Review
This tutorial covered the fundamental concepts underlying the Internet. Take a moment to ponder each of the following terms and paraphrase them internally before clicking elsewhere.
- IP address
- Uniform Resource Locator (URL)
- Hyper-Text (links)
- http://
- World Wide Web (www)
- Transmission Control Protocol / Internet Protocol (TCP/IP)
- C-Class address
- Protocol (standard)
- HTML
- ftp://
If you really want to embed the learning in this tutorial use spaced repetition, scientifically proven to increase retention. Review new material again the next day, again in one week, then again in one month to commit your learning to long-term memory.
Learning more…
In the other tutorials on this site there’s introductions to the languages used to code websites: HTML, CSS & JavaScript; more about the types of server platforms, and server-side code; and finally an overview of Internet Marketing as a whole, with additional details on the most important aspects of marketing online: Email marketing, Web Analytics, Traffic Generation, and Web 2.0 / Social Media.
