The conference function allows more than two parties to communicate over the phone in a virtual conference room. In principle, there is no limit to the number of participants; it all depends on the technical solution made available by the provider in question. It is even possible to hold telephone conferences with hundreds of participants. In order to ensure that only authorised persons are able to participate in the telephone conference, it is customary to protect access by means of a PIN, for example. The digitalisation of telephony and the enhanced technical possibilities it presents are leading to an increase in the significance and popularity of the conference function. In the professional business environment, telephone conferences facilitate savings in travel expenses and time resources, as the number of meetings requiring physical presence can be kept to a minimum. An alternative term for a telephone conference is “conference call”.