Unified Communications (UC) is a marketing buzzword describing the integration of real-time, enterprise, communication services such as instant messaging (chat), presence information, voice (including IP telephony), mobility features (including extension mobility and single number reach), audio, web & video conferencing, fixed-mobile convergence (FMC), desktop sharing, data sharing (including web connected electronic interactive whiteboards), call control and speech recognition with non-real-time communication services such as unified messaging (integrated voicemail, e-mail, SMS and fax). UC is not necessarily a single product, but a set of products that provides a consistent unified user-interface and user-experience across multiple devices and media-types.

In its broadest sense, UC can encompass all forms of communications that are exchanged via a network to include other forms of communications such as Internet Protocol Television (IPTV) and digital signage Communications as they become an integrated part of the network communications deployment and may be directed as one-to-one communications or broadcast communications from one to many.

UC allows an individual to send a message on one medium, and receive the same communication on another medium. For example, one can receive a voicemail message and choose to access it through e-mail or a cell phone. If the sender is online according to the presence information and currently accepts calls, the response can be sent immediately through text chat or video call. Otherwise, it may be sent as a non-real-time message that can be accessed through a variety of media.