It is not always essential to use additional technologies in order to implement concepts and contents of interactive television. A creative combination of conventional media e.g. a classic television, telephone and laptop, already offers many opportunities. Many concepts can also be implemented using tablets.

In many cases however, direct interaction in front of and with the television set is desirable, e.g. in order to direct the contents, to intensify the experience or simply to ease payment. This form of interaction is facilitated by so-called "iTV applications".

In terms of contents, one could compare an iTV application with the "extras" on a DVD. In other words this is a self-contained multimedia offering, although it is based on television contents.

In order to present and interact with iTV applications, one requires a computer unit in or on the television set. There are also further technical requirements such as WAN interfaces or access to the standard functions of the receiver unit.

The effective configuration of iTV applications is difficult.

• For cost reasons, the computer unit often provides a considerably poorer performance than developers and users of PCs or laptops are used to.
• The interfaces between television and TV remote control are different to the customary productive combination of high resolution monitor and mouse.
• The television programme and iTV application share the same output medium. With the majority of viewers not interacting, the television programme must also function fully without iTV applications.
• An iTV application should be attractive and useful both with and without parallel use of tablets.

On the other hand, the iTV applications offer effects and options which no classic media can provide. Central advantages of the media television/receiver and PC/laptop are combined in the iTV application and further enhanced.

• The use of the television as an output medium leads for example to the advantages of constant availability, the emotionally positively charged living room as the interaction space and the use of an often large-scale display.
• The PC utilises the inexhaustible potential of PC applications and the World Wide Web.
• This combination results in the direct interlocking of collective television contents and individual additional offerings. This means for example the absence of a media break and the perfect synchronisation.

This combination promotes many content-based and business concepts such as:

• Individual video contents on demand on the familiar and favoured output medium
• Synchronised and individualised advertisements and teasers
• "1-click" merchandising

Interactive television is often understood in the narrow sense as simply being the provision of iTV applications.

The significance of iTV applications can considerably increase through the arrival of future technologies. Worth a mention are home networks and the use of remote controls with tactile feedback.