Web applications are complex mechanisms which integrate technologies appropriate for the methods that are processed. There are specific languages, document structures, syntax and objects for each level of an application; interface, application and datasource.

The client which processes the interface is normally your computers browser which typically has software to interpret HTML, JavaScript, CSS and possibly Flash.

The application coding language will be determined by your hosting environment, which will be either Windows based or Apache/Linux. This means that the application will be written in either ASP.NET or PHP.

The datasources in a modern web application may consist of a database, web services, RSS feeds, streaming content and flat files. Again, the language used to program this functionality will be determined by your host.