Data broadcast (or datacast as it is often called) is the term used to describe the point to multipoint delivery of electronic information, using spare capacity (the Vertical Blanking Interval or VBI) within broadcast networks such as satellite, television or radio.

The most familiar application of data broadcasting is public service teletext, where any suitably equipped television can receive, decode, store and display hundreds of pages of information. In the UK the TV VBI is used not only for public information services but also for restricted access data communication and DBI's principal business concentrates on its unique ability to provide these commercial, subscription and closed user group services.

Typically, the information provider delivers the data to the system operator (DBI), via a modem or leased line. DBI then formats the data, adds error correction codes and addresses before passing it on to the network operator for insertion into the broadcast signal. The recipient is able to receive the data using an aerial or satellite dish and a decoder which in turn feeds the output device such as a personal computer, TV screen or printer.