HTML describes content on the Web. It tells us which bits are headers, paragraphs, links, and so on. It’s a common misconception that HTML is a programming language, but this isn’t the case at all; HTML by itself enables very little user interaction – it’s simply the means by which Web-pages are encoded.

The Web was built on HTML, and its extreme simplicity drove its quick adoption.

JavaScript is the language used within browsers to make things happen on the user’s PC. JavaScript makes menus pop down, and fields automatically change colour when you enter data.

JavaScript-powered functionality tends to be a non-essential addon to most Websites (indeed, many users choose to disable JavaScript in their browser settings), but it often enhances the user’s experience by making Websites more usable and aesthetically-pleasing.

AJAX (Asynchronous JavaScript And XML) is a special technique in Web development that allows Web-pages to do things “in the background” – avoiding the need to refresh the whole page. AJAX and JavaScript are used extensively to implement sites like online supermarkets and Google’s Gmail and Google Maps.

Adobe Flash is a multimedia platform and runs as a plug-in in most, modern browsers. Flash is used to add video and animation to Web pages, as well as to make them more interactive.

YouTube and the BBC's iPlayer are both examples of Flash-powered applications.

Flash is often criticised for its use of the programming language ActionScript, which many believe is not as robust or well-developed as alternatives.

Silverlight is developed by Microsoft and provides much of the same functionality as Flash. Silverlight includes support for more advanced languages than Flash however, with developers able to exploit the more powerful features offered up by the C# language and the .NET framework.

Silverlight still has a long way to go to outstrip Flash though. Interestingly, ITV’s ITV Player was implemented in Silverlight before a big-budget switch to Flash – their justification was apparently that they’d be able to reach more users with a Flash-based version.

One criticism directed at Microsoft’s Silverlight is that it isn’t cross-platform compatible (it doesn’t operate on Linux systems, for example). However, Novell – in cooperation with Microsoft – develop and maintain a free software version, ‘Moonlight’, which implements most Silverlight functionality on open-source platforms including Linux and FreeBSD.

HTML still provides the backbone of everything on the Web. In this latest incarnation, HTML5 attempts to address the issue of the user having to install third-party software to view and interact with Websites.

The new version incorporates functionality like video playback and drag ’n’ drop – features which would normally require one of either Flash or Silverlight.

Uptake is slow on this new standard, but Blueberry is watching with interest as Wikipedia – a major player - has already taken the decision to include HTML5-standard video in its articles.

ASP.NET is a programming language for the Web. It requires that the server runs a Windows operating system and that the .NET framework is installed. The server-side programming language used in a website is invisible to the user who’s visiting – to them, it doesn’t matter.

PHP is another programming language used in Web development. PHP boasts a tremendous amount of free software, and is spoilt for choice in one category in particular: Content Management Systems.

A CMS provides a platform on which a Website is built. The idea is that, after the technical side of things have been taken care of by developers, the client is left with a system that they can easily maintain and update by adding or changing content.

At Blueberry, we use Drupal. Joomla is also an excellent bit of kit, however.

When Francis Bacon said that “knowledge is power”, it’s safe to say he wasn’t talking about databases. They are, however, a crucial component of any and every Web application.

Most Relational Database Management Systems use SQL (or ‘Structured Query Language’) to create, retrieve, update and delete data – the decision on which to use is largely based on the deployment environment used: MSSQL (Microsoft’s version) requires a Windows operating system, while MySQL is open-source and cross-platform compatible so can run virtually anywhere.