The proliferation of audiovisual communications technologies, including sound, video, lighting, display and projection systems, is evident in every sector of society: in business, education, government, the military, healthcare, retail environments, worship, sports and entertainment, hospitality, restaurants, and museums. The application of audiovisual systems is found in collaborative conferencing which includes video-conferencing, audio-conferencing, web-conferencing and data-conferencing; presentation rooms, auditoriums, and lecture halls; command and control centers; digital signage, and more. Concerts and corporate events are among the most obvious venues where audiovisual equipment is used in a staged environment. Providers of this type of service are known as rental and staging companies, although they may also be served by an in-house technology team.