Internet and IP Addresses

To start our articles on some of the basics of the Internet here is a brief description of Internet addresses - a dry subject to be sure but it is one of the bedrocks of the Internet and how it works - so feel free to read on or skip to our next article about Domain names which has a much more direct and practical impact on those of you looking at starting or developing your website.

What is now known as the Internet started to emerge in the 1960s as a way for government researchers in the US to share data and information via computers.   Among these networks the most significant was ARPANET.   However, these networks could only communicate with other members of their network - there was no common or standardised ‘language’ which allowed different networks to exchange information.

In 1983 a new communications protocol (Transfer Control Protocol/Internetwork Protocol (TCP/IP)) was published which laid out a standardised way for computers to connect, communicate and exchange information.   Thus the internet came into being.

For the general public, the use of the Internet was primarily associated with the early use of email.   The internet started its explosion with the invention of the World Wide Web in 1989.    This added numerous features to the existing protocols which provided a standard way of presenting information.   Created for and Initially used by, scientists and researchers, over the next five or so years the use of the World Wide Web greatly expanded and by 1994 there were more than 10 million users and growth since then has expanded exponentially.

For all these computers to successfully communicate they required some form of identification or address - just as in your home address.   However, to make this work each address would have to be unique.   It was recognised quite early that there would be a need for many of these unique addresses.  Hence a numeric address was developed which is typically written in the form XXX.XXX.XXX.XXX (e.g.    This format allowed for some 4.3 billion unique addresses which at the time was considered more than sufficient for all imagined uses.  It was thus possible to both identify the computer (or host) and provide its location to allow other devices to find and communicate with it.   This address format is now known as  IPv4 addresses.

With the explosion of the World Wide Web and the increasing use of other devices (Internet of Things) that needed to connect via the Internet even the billions of possible addresses would rapidly run out.   A new address format (IPv6) has been created which hopefully may not run out in the foreseeable future - it can represent approximately 3.4 x 10^38 unique addresses! The downside of this is that these addresses when represented in a more compact form are even more unmemorable than the older IPv4 scheme (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).

Today IPv4 and IPv6 coexist but, thankfully, are typically only visible to and an issue for IT professionals.   For a wider audience, a new scheme came to the rescue - Domain Names - the subject of our next blog article.

Previous Post
2 / 2