Digital: The basic building blocks for the whole thing. Where analogue information is made up of streams of electronic signals of varying frequency – streams that degrade as they are copied with each generation getting further away from the original – digital data is made up of ones and zeros, endlessly reproducible, easily exchanged and perfect every time. Digital information is the language of computers and increasingly that of telephony, music, TV and – watch this space – household appliances.

Digital divide: The gap between those whose world is digitally enabled and those whose world is not. Like the economic or media divides before it, this is something that some ignore, some see as potential and some see as a fatal flaw in at the heart of the new e-conomy.

Digital object identifier (DOI): A permanent identifier given to an internet document so that if its internet address changes, users will be redirected to its new address. DOIs are managed by a central directory.

Digital signature: A secure identifier that can be transmitted across digital networks. Long sought after by companies dependent on verifiable content, such as pharmaceutical companies, and now by the Government looking for ways of cutting the costs of the prescription systems.

Decryption: What has been encrypted must be decrypted by the receiver or by the interceptor, hence Government agencies' interest in public encryption systems and the furore about the recent regulation of investigatory powers (RIP) legislation.

Demographics: In a previous economy it was a neat system for identifying, categorising and targeting particular groups with sales messages, products or politics. In the new e-conomy, it is a notoriously slippery and arguably meaningless attempt to pin down fluid communities of interest, conversations and fleeting eyeballs.

Dial-up: Still the main way in which end-users connect to the internet, by a slow modem and a bad phone connection.

Dead media: Sci-fi writer Bruce Sterling has helped to create a list at www.islandnet.com/~ianc /dm/dmlist.html that lists all those technologies which have been left by the side of the information superhighway.

Disintermediation: The process of giving a consumer direct access to information that h

ad traditionally demanded the skills of a librarian, a doctor or – erm, a lawyer.

Domain: The address of a website and source of many a virtual goldrush and legal dispute. The domain name system (DNS) allows addresses to map to IP addresses that are the "real" location of a webpage.

Dotcom: If you have to ask, where have you been for the past 18 months?